RU2313527C1 - Method for preparing 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo[5.2.1.02,6]dec-8-ene-3,5-diones - Google Patents

Abstract

FIELD: chemistry of metalloorganic compounds, chemical technology.

SUBSTANCE: invention relates to methods for synthesis of novel organomagnesium compounds. Method involves interaction of disubstituted acetylenes with butylmagnesium bromide in the presence of a catalyst in argon atmosphere, under atmosphere pressure and temperature ~20⁰C, in ether solvent for 3 h followed by vacuum evaporation of ether, addition of maleic anhydride at temperature -5⁰C and stirring the reaction mass at temperature ~20⁰C in toluene medium for 6-8 h. The yield of the end product is 48-57%. Proposed method provides preparing compound of the formula (1):

wherein R means ethyl (Et), n-propyl (n-Pr), n-butyl (n-Bu) with high selectivity. Synthesis of these compounds is not describes in special literature. Synthesized compounds can be used in fine organic and metalloorganic synthesis and as co-catalysts in processes of oligo- and polymerization of olefins and coupled dienes.

EFFECT: improved method of synthesis.

1 tbl, 10 ex

Description

The present invention relates to methods for producing new organomagnesium compounds (MOS), specifically to a method for producing 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2,6 ] dec-8-en-3, 5-diones of the general formula (1):

The proposed compounds can be used in fine and organometallic synthesis, as well as as cocatalysts in the processes of oligo- and polymerization of olefins and conjugated dienes.

The known method [1, DPLewis, PMMuller, RJWhitby, RVHJones. A zirconium catalysed synthesis of 1,4-dimagnesium reagents // Tetrahedron Lett., 1991, 32, p.6797] for the preparation of cyclic oxygen-containing organomagnesium compounds (2) by reacting 1 - [(4-pentenyloxy) methyl] benzene with diethyl magnesium (MgEt ₂ ) in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ) according to the scheme:

The known method does not allow to obtain 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2.6 ] dec-8-en-3,5-diones (1).

The known method [2, J.-G. Duboudin, B. Jousseaume. Reactifs de Grignard vinyliques γ-fonctionnels: III. Addition a quelques derives carbonyles // J. Organomet. Chem., 1979, 168, p.227] for the preparation of unsaturated cyclic oxygen-containing organomagnesium compounds (3) by reacting disubstituted acetylene with Grignard reagents (RMgBr) in the presence of a copper iodide catalyst (CuI) at room temperature according to the scheme:

In a known manner, 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2.6 ] dec-3-en-3,5-dione (1) cannot be obtained.

Thus, in the literature there is no information on the selective preparation of 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2,6 ] dec-8-en-3,5-diones (1).

A new method is proposed for producing 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2.6 ] dec-3-en-3,5-diones (1).

, где R=Et, н-Pr, н-Bu, с бутилмагнийбромидом (BuMgBr) в присутствии катализатора цирконацендихлорида (Cp₂ZrCl₂), взятыми в мольном соотношении

:BuMgBr:Cp₂ZrCl₂, равном 20:(20-24):(0.4-0.6), предпочтительно 20:22:0.5, в атмосфере аргона при комнатной температуре ~20°С и атмосферном давлении в диэтиловом эфире (Et₂O) в качестве растворителя в течение 3 часов с последующим вакуумированием эфира, добавлением при температуре -5°С малеинового ангидрида в эквимольном по отношению к BuMgBr количестве с перемешиванием реакционной массы 6-8 часов, предпочтительно 7 часов, в толуоле при комнатной температуре (~20°С). Реакция протекает с образованием 1,7,8,9-тетраалкил-4-окса-10-магнезатрицикло[5.2.1.0^2,6]дец-8-ен-3,5-дионов (1) с выходом 48-57% по схеме:The essence of the method consists in the interaction of dialkyl substituted acetylenes of the General formula

where R = Et, n-Pr, n-Bu, with butyl magnesium bromide (BuMgBr) in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ), taken in molar ratio

: BuMgBr: Cp ₂ ZrCl ₂ equal to 20: (20-24) :( 0.4-0.6), preferably 20: 22: 0.5, in an argon atmosphere at room temperature ~ 20 ° C and atmospheric pressure in diethyl ether (Et ₂ O ) as a solvent for 3 hours, followed by evacuation of ether, addition of maleic anhydride at a temperature of -5 ° C in an amount equimolar to BuMgBr with stirring of the reaction mixture for 6-8 hours, preferably 7 hours, in toluene at room temperature (~ 20 ° C). The reaction proceeds with the formation of 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2,6 ] dec-8-en-3,5-diones (1) with a yield of 48-57% scheme:

1,7,8,9-Tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2.6 ] dec-8-ene-3,5-dione (1) are formed only with the participation of BuMgBr, disubstituted acetylenes, zirconium catalyst Cp ₂ ZrCl ₂ and maleic anhydride. In the presence of other magnesium compounds (e.g., PhMgBr, Ph ₂ Mg, AllMgBr, MeOMgBr), other acetylenes (e.g., terminal), other catalysts (e.g., Zr (acac) ₄ , Cp ₂ TiCl ₂ , Pd (acac) ₂ , Ni (acac) ₂ , NiCl ₂ , Fe (acac) ₂ ), other carboxylic acid anhydrides (e.g., acetic or phthalic anhydrides), the desired products (1) are not formed.

The reactions were carried out at room temperature (~ 20 ° C). At a higher temperature (for example, 40 ° C), there is no significant increase in the yield of the target products (1), and at a lower temperature (for example, 0 ° C), the reaction rate decreases.

A change in the ratio of the starting reagents (BuMgBr, maleic anhydride) and the catalyst (Cp ₂ ZrCl ₂ ) upward relative to the starting disubstituted acetylene (R-≡-R) does not significantly increase the yield of the target products (1). A change in the ratio of the starting reagents and the catalyst in the direction of their decrease with respect to the starting disubstituted acetylene reduces the yield of the target products (1).

Significant differences of the proposed method.

In the proposed method for the production of unsaturated cyclic oxygen-containing MOS, dialkyl substituted acetylenes (R-≡-R), maleic anhydride and a Cp ₂ ZrCl ₂ catalyst are used as starting compounds. In the known method, unsaturated cyclic oxygen-containing MOS are obtained from propargyl alcohols with the participation of a CuI catalyst.

The proposed method has the following advantages:

The method allows to obtain with high selectivity 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2,6 ] dec-8-en-3,5-diones (1), the synthesis of which in the literature not described.

The method is illustrated by the following examples.

EXAMPLE 1. In a 50 ml glass reactor mounted on a magnetic stirrer, 5 ml of Et ₂ O, 20 mmoles of hex-1-in are placed under argon atmosphere. The mixture is cooled to 0 ° C, 0.5 mmol of Cp ₂ ZrCl ₂ catalyst, 22 mmol of BuMgBr catalyst (in Et ₂ O) are added and stirred for 3 hours at a temperature of ~ 20 ° C, then ether is evacuated, 6 ml of toluene and 12 mmol of maleic anhydride are added at a temperature of -5 ° C, after which the reaction mass is stirred for 7 hours at a temperature of ~ 20 ° C. Obtain 1,7,8,9-tetraethyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2.6 ] dec-8-en-3,5-dione (1) with a yield of 55%. The yield of the target product is determined by the hydrolysis product (4).

Spectral characteristics of 4,5,6,7-tetraethyl-3a, 4,7,7a-tetrahydro-1,3-isobenzofuran-2,9-dione (4): ¹³ C NMR spectrum of CDCl ₃ , δ, ppm : 172.44 (C ² , C ⁹ ), 42.68 (C ³ , C ⁸ ), 41.68 (C ⁴ , C ⁷ ), 138.42 (C ⁵ , C ⁶ ), 20.70 (C ¹⁰ , C ¹⁶ ), 12.53 (C ¹¹ , С ¹⁷ ), 20.01 (С ¹² , С ¹⁴ ), 14.90 (С ¹³ , С ¹⁵ ). Other examples confirming the method are given in table 1.

Table 1 No. Starting disubstituted acetylene, R-≡-R The molar ratio of R-≡-R: BuMgBr: Cp ₂ ZrCl ₂ : maleic anhydride, mmol Reaction time, hour Yield (1),% one 2 3 four 5 one. Et-≡-Et Hexin-3 20: 22: 0.5: 22 10 1,7,8,9-tetraethyl-4-oxa-10-magnesa-tricyclo [5.2.1.0 ^2,6 ] -dec-8-ene, 55 2. - "- 20: 24: 0.5: 24 10 - "-, 56 3. - "- 20: 20: 0.5: 20 10 - "-, 52 four. - "- 20: 22: 0.6: 22 10 - "-, 57 5. - "- 20: 22: 0.4: 22 10 - "-, 48 6. - "- 20: 22: 0.5: 22 eleven - "-, 54 7. - "- 20: 22: 0.5: 22 9 - "-, 51 8. Pr-≡-Pr octin-4 20: 22: 0.5: 22 10 1,7,8,9-tetra- (n-propyl) -4-oxa-10-magnesatricyclo [5.2.1.0 ^2,6 ] -dec-8-ene, 54 9. Bu-≡-Bu Decin-4 20: 22: 0.5: 22 10 1,7,8,9-tetra- (n-butyl) -4-oxa-10-magnesatricyclo [5.2.1.0 ^2,6 ] -dec-8-ene, 49

The reactions were carried out at a temperature of ~ 20 ° C.

Claims (1)

The method of obtaining 1,7,8,9-tetraalkyl-4-oxa-10-magnesatricyclo [5.2.1.0 ^2,6 ] dec-B-en-3,5-diones (1) of the general formula:

where R = Et, n-Pr, n-Bu consisting in the fact that disubstituted acetylenes of the general formula R-≡-R, where R is Et, n-Pr, n-Bu, are reacted with BuMgBr butyl magnesium bromide in the presence of a Cp ₂ ZrCl ₂ zirconacene dichloride catalyst in the molar ratio R-≡-R: BuMgBr : Cp ₂ ZrCl ₂ equal to 20: 20-24: 0.4-0.6, in an argon atmosphere at atmospheric pressure and room temperature ~ 20 ° C in diethyl ether as a solvent for 3 hours, followed by evacuation of the ether and adding at a temperature of -5 ° С maleic anhydride taken in an amount equimolar to BuMgBr, with stirring the reaction mass for 6-8 hours at room temperature ~ 20 ° C in toluene.