Process for preparing aromatic acetic acid

Claim 1

A process for preparing an aromatic acetic acid represented by the formula ArCH.sub.2 COOH wherein Ar is a substituted or unsubstituted aromatic selected from the group consisting of the following groups (a), (b) and (c): (a) a group of the formula ##STR18## wherein R 1 and R 2 may be at the same or different and each represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a phenoxy group, a benzyloxy group or R 1 and R 2 may cooperate to form a lower alkylidenedioxy group; (b) a group of the formula: ##STR19## wherein R 1 and R 2 are the same as defined above; and (c) a group of the formula ##STR20## wherein A represents an oxygen atom (O), a sulfur atom (S) or a >NR 6 group in which R 6 is a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms, and R 3 represents a hydrogen atom or a lower alkyl substituted benzoyl group; which comprises reacting an aromatic aldehyde represented by the formula ArCHO wherein Ar has the same meaning as defined above, with a trihalomethane represented by the formula HCX.sub.3 wherein X represents at least one halogen selected from the group consisting of chlorine and bromine atoms, in the presence of a base in a mixed medium of water and an aprotic polar solvent to form an alcohol derivative represented by the formula ##STR21## wherein Ar has the same medium as defined above, and then reacting the thus formed alcohol derivative with an alkanethiol represented by the formula RSH wherein R is an alkyl group, in the presence of a base in a mixed medium of water and an aprotic polar solvent, wherein the volume ratio of said water and said aprotic polar solvent is 1:0.2-1:5.