CS240706B1 - Method of cinnamaldehyde production - Google Patents

Description

The invention relates to a process for the production of cinnamon aldehyde. ...

Cinnamon aldehyde ^: (3-phenylbiphenyl) is one of the major raw materials of the cosmetic industry. The most commonly used method of making cinnamon aldehyde is the aldol condensation of benzaldehyde with acetaldehyde (Kirk ---- Othmer: Encyclopedia of Chemical Technology, vol. 5, p. 520). Cinnamic aldehyde can also be obtained with a low yield (45%) of 1,3,3-chloro-3-phenylcaropaine by the action of sodium ethoxide (J. Chem. Soc. 1963, 3 921).

A more efficient way to produce cinnamon aadehyde yielding over 90% yields is to convert 1,1,3-trichloro-3-phenol-yoyan by either catalytic catalytic hydrolysis and hydrolysis (U.S. Pat. No. 226,991) or subsequent alkaline dehydrogenation. hydrolysis (cf. No. 226 995); 1,1,3-trichloro-3-lenzepropane is readily available by catalytic radical addition of chloroform to styrene (US Patent No. 236,974).

SUMMARY OF THE INVENTION The present invention provides a process for the production of cinnamic aldehyde from 1S, 5-trichloro-S-phenylpropane, which comprises allowing a portion of mol. 1,1,3-trichloro-3-eno-yoopane, 2 to 10 parts by mol. methanol or ethanol, 2-4 parts by mol. alkali metal hydroxide and: up to 20 parts mol. water or 4 to 20 parts of a 20 to 50% aqueous alkali metal hydroxide solution at once or one or two components are added sequentially, the resulting mixture is heated at 65 to 120 ° C and then directly or after separation of the aqueous layer by inorganic the mixture is heated to boiling until the hydrogen chloride is released and the resulting cinnamic aldehyde is isolated.

An advantage of the process of making the cinnamic aldehyde according to the invention is a simpler and more economical embodiment, whereby rectification yields a cinnamic aldehyde having a purity of up to 100%.

The examples below illustrate the process for making cinnamic aldehyde of the invention without limiting or limiting its scope.

• Example 1

In a glass flask equipped with a reflux condenser and stirrer was charged 67.0 g of - (0-, 3 mol) 1,1,3-tri-chloro-3-phenylpolyol and 76 ml (1.85 mol) of methanol. heating the reaction mixture to boiling is gradually added over a period of 1 h. g (0.75 mol) of a 50% aqueous potassium hydroxide solution is continued for 8 hours while heating to boiling. Thereafter, 160 ml of dilute 5% hydrochloric acid was added to the reaction mixture, and the methanol was not distilled. The mixture was cooled, the organic layer was separated and washed with water. Distillation under reduced pressure yielded 36.9 g (93% of theory) of cinnamic aldehyde, m.p. 116 DEG C./15 mbar, 98.1% purity. ·

Example 2

A glass flask equipped with a condenser and a stirrer was charged with 67.0 [0.3 mol) '1 ^, I ^ ^b ťr1c3lor 3-fenylyroyanu and 75 ml (1.281 m'ol) ethanol after heating the reaction mixture to varu- 90 g (0.9 mol) of a 40% aqueous solution of sodium hydroxide are gradually added over 1 hour and heating is continued for 3 hours. After 'cooling', the reaction mixture is neutralized with dilute hydrochloric acid to pH 7, ethanol is distilled off, the organic layer is separated and mixed with 100 ml of 0.4% hydrochloric acid and heated to boiling for 2.5 h.

The mixture is cooled, the organic layer is separated, washed with water and distilled under reduced pressure to isolate: 36.5 g (92% of theory) of cinnamic aldehyde, m.p. 122 DEG C. at 1.7 kPa and a purity of 97.7%.

Example 1 a d 3

Into a glass flask fitted with. 720 ml (40 moles) of water, 432 g (10.8 moles) of sodium hydroxide and 8.5 g (3.6 moles) of 1,1,3-trichloro-3-phenylpyride are charged with a condenser and stirrer. After heating to 78 [deg.] C., 1800 ml (30.8 mol) of ethanesium is added gradually over 4 hours and heating is continued for 0.5 hours. Then, 330 ml of 30% hydrochloric acid are added to the reaction mixture, and ethanol is distilled off. The mixture was cooled, the organic layer was separated and washed with water, and then 476 g (91% of theory) of cinnamic aldehyde, m.p.

Claims (1)

OBJECT OF THE INVENTION • A process for the production of cinnamic aldehyde from 1,1,3-thichichlo-3-phenylprupane, characterized in that it is reacted - 1 part mol. 1,1,3-toich-or-3-phenyloopane, 2 to 10 parts by mol. methanol or ethanol, 2-4 parts by mol. alkali metal hydroxide and from 1 to 20 parts by mol. water or 4 to 20 parts of a 20 to 50% aqueous alkali metal hydroxide solution at once or one or two components are added sequentially, the resulting mixture heated at 65 to 120 ° C and then directly or after - adjust the pH to 1 to 7 with inorganic acid, heat the mixture to boiling until hydrogen chloride is released and the resulting cinnamic aldehyde is isolated.