CN107522615A - Synthesis method of beta-iodoformate compound - Google Patents

Abstract

The invention discloses a method for synthesizing a β-iodoformate compound shown in a formula II, using a styrene compound shown in formula I as a raw material, using zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^‑ ‑LDHs intercalated with bromate as an oxidant, and an iodide as a reducing agent, and reacting in formic acid at 15-60° C. for 1-6 hours, and the resulting reaction solution is post-processed to obtain a β-iodoformate compound shown in formula II. The formic acid used in the present invention not only provides an acidic chemical reaction environment, but also directly adds esterification as a nucleophilic reagent, which belongs to an atom-economic reaction; the iodine source used in the present invention is simple and easy to obtain, and the reaction conditions are mild, environmentally friendly, and simple to operate.

Description

A kind of synthetic method of β-iodoformic acid ester compound

(1) Technical field

The invention relates to a method for synthesizing organic compounds, in particular to a method for synthesizing β-iodoformate compounds.

(2) Background technology

The ortho-bifunctionalization of carbon-carbon double bonds is an important reaction in the field of organic chemistry, especially β-iodoformate compounds are an important class of reaction intermediates in organic synthesis, which can undergo various transformations to obtain Drug molecules and active natural products. For example: due to the low bond energy of the carbon-iodine bond, the structure can undergo a cross-coupling reaction under the catalysis of palladium to increase the carbon chain; of various organic compounds.

At present, there are very few synthetic methods about β-bromoformate reported at home and abroad, and there are mainly the following methods: (1) elemental iodine and N,N-dimethylformamide and styrene compounds synthesize β-bromine Formic acid ester compounds (see Prasad PK, Reddi R N, Sudalai A. Chemical Communications, 2015, 51(51): 10276.), this method has a low yield, and the direct use of elemental iodine causes greater environmental pollution. (2) Ammonium iodide and potassium hydrogen persulfate compound salts synthesize β-iodoformate compounds with styrene compounds in the presence of N,N-dimethylformamide (see Durgaiah C, Naresh M, Kumar MA, et al. al.Synthetic Communications, 2016(13).), due to the use of N,N-dimethylformamide in this method, the post-treatment process after the reaction is more complicated, which increases the difficulty of product separation and analysis.

In view of the above problems, it is necessary to design a new method for the synthesis of β-iodoformate compounds with good atom economy, simple operation, low toxicity and environmental friendliness.

(3) Contents of the invention

In order to solve the problems of high toxicity, environmental pollution and high cost in the current method for synthesizing β-iodate compounds, the present invention proposes a method for preparing β-iodoformate compounds. The synthetic method of the present invention overcomes the Shortcomings of the prior art.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

Using the styrene compound shown in formula I as raw material, zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs intercalated with bromate as oxidant, and iodide as reducing agent, react in formic acid at 15-60°C for 1- After 6 hours, the resulting reaction solution was post-treated to obtain the β ^- iodoformate compound shown in _formula II; The amount of the styrene compound shown in I is 0.35～0.55g/mmol; the volume consumption of the formic acid is 4～8mL/mmol based on the amount of the styrene compound shown in the formula mmol; the ratio of the amount of the iodide to the styrene compound represented by the formula I is 1 to 2:1;

In formula I or formula II:

R ¹ is one of H, -CH ₃ , -OC(=O)-CH ₃ , Br or Cl.

Further, the iodide is potassium iodide, sodium iodide, lithium iodide or ammonium iodide, preferably potassium iodide.

Further, preferably, the reaction temperature is 25° C., and the reaction time is 3 hours.

Further, it is preferred that the mass of the bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ⁻ -LDHs calculated by the amount of the styrene compound represented by formula I is 0.4 g/mmol.

Further, preferably, the ratio of the amount of the iodide to the styrene compound represented by the formula I is 1.1:1.

Further, preferably, the volumetric amount of the formic acid is 5 mL/mmol based on the amount of the styrene compound represented by the formula I.

The post-treatment method of the reaction liquid of the present invention is as follows: after the reaction is finished, the obtained reaction liquid is centrifuged to remove the zinc-aluminum hydrotalcite solid, the obtained liquid is placed in a separatory funnel, dichloromethane and deionized water are added, and the organic phases are combined, Column chromatography silica gel was added to the resulting solution, the solvent was distilled off under reduced pressure, the remaining mixture was separated by column chromatography, and the mixed solvent containing petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as an eluent to collect the mixture containing the target product. The eluent, the eluent is evaporated to remove the solvent to obtain the β-iodoformate compound shown in formula II.

Furthermore, it is recommended that the synthetic method of the present invention be carried out in accordance with the following steps:

Using the styrene compound shown in formula I as raw material, zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs intercalated with bromate as oxidant, and potassium iodide as reducing agent, after reacting in formic acid at 25°C for 3 hours, the reaction After the end, the obtained reaction solution was centrifuged to remove the zinc-aluminum hydrotalcite solid, the obtained liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic phase was combined, and column chromatography silica gel was added to the obtained solution, which was then removed by distillation under reduced pressure. Solvent, the remaining mixture is separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 is used as an eluent to collect the eluent containing the target product, and the eluent is evaporated to remove the solvent Obtain the β-iodoformate compound shown in formula II; The quality of the zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs of described bromate intercalation is the material of the styrene compound shown in described formula I The amount of the formic acid is 0.4g/mmol; the volumetric amount of the formic acid is 5mL/mmol based on the amount of the styrene compounds shown in the formula I; the potassium iodide and the formula I The ratio of the amount of styrenic compound to substance is 1.1:1.

Compared with prior art, the beneficial effect of the present invention is:

(1) The formic acid used in the present invention not only provides an acidic chemical reaction environment, but also acts as a nucleophile for direct addition esterification, which belongs to an atom-economic reaction, and fully exerts the acidity, solubility, and nucleophilicity of formic acid.

(2) The iodine source is simple and easy to obtain, the reaction conditions are mild, the environment is friendly, the operation is simple, and the yield of the target product is high.

(4) Specific implementation methods

The present invention will be described in further detail below in conjunction with specific embodiment, but protection scope of the present invention is not limited thereto:

The zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs of bromate intercalation used in the present invention, those skilled in the art can according to existing literature (Wang Ligeng, Zheng Feixiang, Jiang Chenxing, Ni Zheming. Journal of Silicates, 2015, 43 (5): 672-677.) Self-prepared by the published method. (protection scope of the present invention is not limited to this)

Weigh 7.55g of NaBrO ₃ to form a 100mL solution and add it to a four-neck flask as the bottom solution. Weigh 29.75g Zn(NO ₃ ) ₂ . 6H ₂ O and 18.75g Al(NO ₃ ) ₃ . 9H ₂ 0 was configured into 200mL mixed salt solution. Weigh 12.00g NaOH to make 200mL lye. Slowly add the mixed salt solution and lye into the four-necked flask simultaneously by the double-drop method, and vigorously stir (1000r/min) at room temperature to adjust the dropping speed to keep the pH value at 7.0+0.2, and continue to stir for 0.5h after the dropwise addition. The resulting slurry was crystallized at 70°C for 24 hours, filtered and washed, dried at 60°C for 18 hours and then ground. The product was ZnAl-BrO ₃ ^- -LDHs.

Example 1

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 86% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 2

Add 2mmol (0.366g) of 4-bromostyrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs, magnetically stirred at 50°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a pale yellow liquid in 87% yield.

Characterization data: yellow solid, melting point: 51-53°C. ¹ H NMR (500MHz, CDCl ₃ )δ8.14(s,1H),7.54–7.52(m,2H),7.27–7.25(m,2H),5.96–5.93(m,1H),3.48(qd,J =10.7, 6.5Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.41, 136.76, 131.98, 128.19, 123.09, 74.36, 6.31; HRMS (ESI, m/s): Calculated for C ₉ H ₈ BrIO ₂ ( M+H) ⁺ 254.8831, found 254.8829.

Example 3

Add 2mmol (0.277g) of 4-chlorostyrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs, magnetically stirred at 50°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 82% yield.

Characterization data: yellow solid, melting point: 52-53°C. ¹ H NMR (500MHz, CDCl ₃ ) δ8.14(s, 1H), 7.38(dd, J=8.3, 1.4Hz, 2H), 7.32(d, J=8.5Hz, 2H), 5.98–5.95(m, 1H), 3.48 (qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.42, 136.25, 134.92, 129.02, 127.91, 74.32, 6.41; HRMS (ESI, m/s): Calculated for C ₉ H ₈ ClIO ₂ (M+H) ⁺ 310.9336, found 310.9335.

Example 4

Add 2mmol (0.324g) of 4-acetoxystyrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-neck flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl -BrO ₃ ^- -LDHs, magnetically stirred at 25°C for 4 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 85% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ )δ8.14(s,1H),7.41–7.38(m,2H),7.14–7.11(m,2H),6.01(dd,J=8.0,5.2Hz,1H), 3.51(dd, J=10.7, 8.1Hz, 1H), 3.47(dd, J=11.0, 5.4Hz, 1H), 2.31(s, 3H); ¹³ C NMR(126MHz, CDCl ₃ ) δ169.16, 159.48, 151.00, 135.26, 127.68, 121.97, 74.48, 21.10, 6.56; HRMS (ESI, m/s): Calculated for C ₁₁ H ₁₁ IO ₄ (M+H) ⁺ 334.9780, found 334.9783.

Example 5

Add 2mmol (0.208g) of styrene and 2.0mmol (0.3320g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 84% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 6

Add 2mmol (0.208g) of styrene and 4.0mmol (0.6640g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid and the yield was 85.8%.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 7

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.70g of bromate-intercalated zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 71% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 8

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-neck flask, then add 10mL of formic acid as a solvent, and then add 1.1g of bromate-intercalated zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 86% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 9

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 8.0mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs, stirred magnetically at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a pale yellow liquid in 80% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 10

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 16mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid and the yield was 85.7%.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 11

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 15°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a pale yellow liquid in 80% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 12

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 60°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 83% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 13

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ -- LDHs, stirred magnetically at 25°C for 1 hour, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 70% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500 MHz, CDCl ₃ ) δ8.17 (d, J=7.1 Hz, 1H), 7.41–7.37 (m, 5H), 6.02 (dd, J=7.7, 5.5Hz, 1H), 3.52 (qd , J=10.7, 6.7 Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ (M+H)+276.9725, found 276.9727.

Example 14

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3652g) of potassium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc-aluminum hydrotalcite ZnAl-BrO ₃ ^- - LDHs were magnetically stirred at 25°C for 6 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 85% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 15

Add 2mmol (0.208g) of styrene and 2.2mmol (0.1909g) of lithium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- LDHs, stirred magnetically at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 84% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 16

Add 2mmol (0.208g) of styrene and 2.2mmol (0.2264g) of sodium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated ZnAl _- BrO3 ^- LDHs, stirred magnetically at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 85% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Example 17

Add 2mmol (0.208g) of styrene and 2.2mmol (0.3190g) of ammonium iodide into a 50mL three-necked flask, then add 10mL of formic acid as a solvent, and then add 0.8g of bromate-intercalated zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- LDHs, stirred magnetically at 25°C for 3 hours, followed by TLC to complete the reaction. After the reaction, the resulting reaction solution was centrifuged at 6500r/min to remove the zinc-aluminum hydrotalcite solid, the resulting liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic matter obtained from the reaction was extracted into the dichloromethane phase In the obtained solution, column chromatography silica gel was added, and the solvent was distilled off under reduced pressure, and the remaining mixture was separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 was used as the eluent to collect the product containing The eluent was evaporated to remove the solvent to obtain the pure product. The material was a light yellow liquid, 85% yield.

Characterization data: Yellow oily liquid. ¹ H NMR (500MHz, CDCl ₃ ) δ8.17(d, J=7.1Hz, 1H), 7.41–7.37(m, 5H), 6.02(dd, J=7.7, 5.5Hz, 1H), 3.52(qd, J=10.7, 6.7Hz, 2H); ¹³ C NMR (126MHz, CDCl ₃ ) δ159.56, 137.78, 128.99, 128.77, 126.44, 75.10, 6.87; HRMS (ESI, m/s): Calculated for C ₉ H ₉ IO ₂ ( M+H) ⁺ 276.9725, found 276.9727.

Claims (9)

1. a synthetic method of β-iodoformic acid ester compounds shown in formula II, is characterized in that, described synthetic method is specifically carried out according to the following steps: Using the styrene compound shown in formula I as raw material, zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs intercalated with bromate as oxidant, and iodide as reducing agent, react in formic acid at 15-60°C for 1- After 6 hours, the resulting reaction solution was post-treated to obtain the β ^- iodoformate compound shown in _formula II; The amount of the styrene compound shown in I is 0.35～0.55g/mmol; the volume consumption of the formic acid is 4～8mL/mmol based on the amount of the styrene compound shown in the formula mmol; the ratio of the amount of the iodide to the styrene compound represented by the formula I is 1 to 2:1; In formula I or formula II: R ¹ is one of H, -CH ₃ , -OC(=O)-CH ₃ , Br or Cl. 2. The method according to claim 1, characterized in that: said iodide is potassium iodide, sodium iodide, lithium iodide or ammonium iodide. 3. The method according to claim 2, characterized in that: said iodide is potassium iodide. 4. The method according to claim 1, characterized in that: the reaction temperature is 25°C, and the reaction time is 3h. 5. the method for claim 1 is characterized in that: the zinc-aluminum hydrotalcite ZnAl-BrO _of described bromate intercalation ^-- LDHs quality is the amount of the substance of the styrene compounds shown in formula I Calculated as 0.4 g/mmol. 6. The method according to claim 1, characterized in that: the ratio of the amount of said iodide to said styrene compound represented by formula I is 1.1:1. 7. The method according to claim 1, characterized in that: the volumetric dosage of the formic acid is 5mL/mmol in terms of the amount of styrene compounds shown in formula I. 8. The method as claimed in claim 1, characterized in that the post-treatment method of the reaction solution is as follows: after the reaction, the gained reaction solution is centrifuged to remove the zinc-aluminum hydrotalcite solid, the gained liquid is placed in a separatory funnel, and Dichloromethane and deionized water were combined into the organic phase, and column chromatography silica gel was added to the resulting solution, and the solvent was distilled off under reduced pressure. The remaining mixture was separated by column chromatography, and the volume ratio of petroleum ether and ethyl acetate was 10:1. The mixed solvent is used as an eluent, and the eluent containing the target product is collected, and the solvent is evaporated from the eluent to obtain the β-iodoformate compound represented by formula II. 9. The method according to claim 1, characterized in that: the synthetic method is specifically carried out according to the following steps: Using the styrene compound shown in formula I as raw material, zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs intercalated with bromate as oxidant, and potassium iodide as reducing agent, after reacting in formic acid at 25°C for 3 hours, the reaction After the end, the obtained reaction solution was centrifuged to remove the zinc-aluminum hydrotalcite solid, the obtained liquid was placed in a separatory funnel, dichloromethane and deionized water were added, and the organic phase was combined, and column chromatography silica gel was added to the obtained solution, which was then removed by distillation under reduced pressure. Solvent, the remaining mixture is separated by column chromatography, and the mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1 is used as an eluent to collect the eluent containing the target product, and the eluent is evaporated to remove the solvent Obtain the β-iodoformate compound shown in formula II; The quality of the zinc aluminum hydrotalcite ZnAl-BrO ₃ ^- -LDHs of described bromate intercalation is the material of the styrene compound shown in described formula I The amount of the formic acid is 0.4g/mmol; the volumetric amount of the formic acid is 5mL/mmol based on the amount of the styrene compounds shown in the formula I; the potassium iodide and the formula I The ratio of the amount of styrenic compound to substance is 1.1:1.