Mercapto-acetaldehyde acetal(s) prepn. - by using chloro-acetaldehyde acetal(s) and synthetic intermediates from opt. continuous process

摘要

Prepn. of mercaptoacetaldehyde acetals of formula (I) from haloacetals and mercapto cpds. comprises, a) mixing the chloroacetalaldehyde acetals (II) with aq. MSH soln. (m = alkali metal) in a reactor and heating to 80-100 deg.C b) removing the mixt. from the reactor as an organic phase and extracting (I) with aq. alkali, hydroxide soln, c) form the alkali metal salts of (I) solution, d) retwining the organic phase with unreacted (II) to the reactors, d) neutralising the aq. soln. of alkali salts of (II) and e) purifying (I) by distillation. R1, R2 = 1-2C alkyl, or R1+R2 = CH2CH2 or CH2CH(CH3). Cpds. (I) where R1 and R2 are present as R1+R2 are new. Pref. the MSH soln. is at pH 8-95. The process is carried out under a pressure of 0.1-0.2 mPa, in a water immiscible organic solvent which does not react with starting materials or prods. USE/ADVANTAGE - (I) are intermediates in the prepn. of pharmaceuticals, medicines and aromatic substances. The process may be continuous and gives good yields.