Process for preparing aminobenzoic acid derivatives

A process for producing the aminobenzoic acid derivative or the pharmacologically acceptable salt thereof having the formula:

• ##STR86## wherein R.sup.3 represents a halogen atom and R.sup.5 represents a lower alkynyl group having 3 to 10 carbon atoms which may be substituted, which comprises reacting a 4-amino-5-halogen-salicylic acid derivative, wherein the amino group is protected with an acyl, carboxyl or alkyl group and the carboxylic group is protected with a lower alkyl, arylalkyl, arylalkenyl, aryl or halogen-substituted lower alkyl, with a C.sub.2 -C.sub.8 straight or branched chain alkynol in the presence of triphenylphosphine and dialkylazocarboxylate, followed by deprotecting the protective groups.