GB605737A - Improvements in or relating to the production of esters of hydroxy-alkoxy benzoic acids - Google Patents

Abstract

Esters of hydroxyalkoxy-benzoic acids of the general formula <FORM:0605737/IV(b)/1> wherein the -OCH2CHOHCH2OH group is in the ortho-, meta- or para-position to the COOR group, X represents hydrogen, an alkyl group including unsaturated alkyl, a substituted hydroxyl group or a nitro group and R represents an alkyl or an hydroxyalkyl group, are prepared either by esterifying a hydroxybenzoic acid to form an ester of the acid and thereafter reacting the ester with an a -mono-halogenohydrin, or reacting the hydroxybenzoic acid with an a -monohalogenohydrin to form the b : g -dihydroxypropoxybenzoic acid and thereafter converting the b : g -dihydroxypropoxybenzoic acid to the required ester. Normal methods for the formation of esters from acids may be employed, e.g. the hydroxybenzoic or b : g -dihydroxypropoxybenzoic acid may be treated with an alcohol and acid or with a diazohydrocarbon, or the substituted benzoic acid may be converted into the corresponding acid halide which is then reacted with an alcohol or metal alcoholate, or an ester of the substituted benzoic acid may be converted into another ester by treatment with the metal alcoholate corresponding to the alcohol of the ester required, or an ester of hydroxybenzoic acid may be reacted with an a -monohalogenohydrin to form the ester of the b : g -dihydroxypropoxybenzoic acid which ester is hydrolysed to form the free acid which may then be esterified. In examples: (1) to (12) and (19), the preparation of the ethyl, n-propyl and n-butyl esters of p-hydroxybenzoic and p-(b : g -dihydroxypropoxy) benzoic acids and the methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, n-amyl, iso-amyl and hexyl esters of m-hydroxybenzoic and m-(b : g -dihydroxypropoxy) benzoic acids is described; (13) and (14), the ethyl and n-butyl esters of o-(b : g -dihydroxypropoxy) benzoic acid are prepared; (15) b - hydroxyethyl - o - (b : g - dihydroxypropoxy)-benzoate is prepared; (16), (17), (18), (20) and (21), butyl esters of nitro-(b : g -dihydroxypropoxy) benzoic acids are prepared, including n - butyl - 3 - nitro - 4 - (b : g - dihydroxy - propoxy) benzoate and n - butyl - 4 - nitro - 3 - (b : g - dihydroxypropoxy) - benzoate; (22) and (23) methyl - m - (b : g - dihydroxypropoxy) ben - zoate and buty-3-allyl-4-(b : g -dihydroxypropoxy) benzoate are prepared. n-Butyl-3-nitro-4-hydroxybenzoate and n-butyl-4-nitro-3-hydroxybenzoate are prepared by nitrating n-butyl-p-hydroxybenzoate and n-butyl-m-hydroxybenzoate respectively. n - Butyl - 3 - amino - 4 - (b : g - dihydroxypropoxy) benzoate and n-butyl-4-amino-3-(b : g -dihydroxypropoxy) benzoate are prepared by reducing the corresponding nitro substituted compounds with hydrogen and Raney nickel. n - Butyl - 3 - diethylamino - 4 - (b : g - dihydroxy - propoxy) benzoate is prepared by refluxing the corresponding amino substituted compound with ethyl iodide.