BENZALDEHYDE PRODUCTION PROCESS Russian patent published in 2002 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: process includes two-stage hydrolysis of benzal chloride or chlorine-containing aromatic compounds with weight portion of benzaldehyde within a range of 75 to 95%. In the first stage, acid hydrolysis involving 15- 26% aqueous hydrochloric acid solution is carried out at 100-120 C and atmospheric or excessive (up to 1.7 atm) pressure, benzaldehyde-to-hydrochloric acid solution weight ratio being within the limits between 1:0.9 and 1:2.0. In the second stage, supplementary hydrolysis of the first-stage crude benzaldehyde is carried out with 5-20% aqueous sodium carbonate solution or 5- 18% aqueous sodium hydroxide solution at 100-110 C and atmospheric or excessive (up to 1.7 atm) pressure, customarily in presence of interface transfer catalyst taken in amounts from 0.02 to 0.5% of the weight of initial benzaldehyde. EFFECT: enhanced process efficiency. 11 cl, 1 tbl, 4 ex