GB352474A - A process for the manufacture and production of acetals - Google Patents

Abstract

Acetals of the general formula <FORM:0352474/IV/1> where R1 and R2 signify alkyl, aryl, aralkyl or hydrogen, R3 alkyl, aryl or aralkyl, and R4 alkyl, halogen-alkyl, cycloalkyl, aryl, aralkyl or unsaturated alkyl, are manufactured by the action of organic hydroxy-compounds containing more than 1 carbon atom in the molecule and free from carboxylic groups (including mono- and polyhydric open chain or p cyclo-aliphatic, halogen-substituted aliphatic, unsaturated aliphatic and aromatic alcohols, and phenols), on vinyl ethers of the general formula CHR1: CR2. OR3. The reaction may be accelerated by means of acid reacting agents such as boron fluoride or mineral acids, e.g. sulphuric or phosphoric acid, halides of mineral acids, e.g. thionyl chloride, acid salts, e.g. sodium bisulphate, or organic compounds capable of splitting off halogen hydracids, e.g. ethyl-(a -chloroethyl)-ether, or neutral salts such as calcium chloride, or phenols when the reacting hydroxy-compound is not a phenol, and may be carried out at elevated temperature or at a pressure above atmospheric, and with or without the addition of inert organic solvents or diluents such as ether or chloroform or excess alcohol. In examples the following acetals are prepared: (1) acetaldehyde-ethyl-n-butyl acetal from vinyl ethyl ether and butanol or from vinyl-n-butyl ether (obtainable from sodium-n-butylate and vinyl chloride) and ethyl alcohol; (2) acetaldehyde-ethyl-phenyl acetal from vinyl ethyl ether and phenol or from vinyl phenyl ether and ethyl alcohol; (3) acetaldehyde-ethyl-2-chloroethyl acetal from vinyl ethyl ether and ethylene chlorhydrin; (4) symmetrical di-(acetaldehyde-ethyl)-1.2-ethylene acetal, of the formula <FORM:0352474/IV/2> vinyl ethyl ether and ethylene glycol; (5) acetaldehyde-ethyl-chlolesteryl acetal from vinyl ethyl ether and cholesterol. The products may be employed as solvents or softening-agents or in pharmacy.