3-Amino-4-hydroxybenzoic acid → 2-(4-Carbomethoxyphenyl)-5-carboxybenzoxazole

Participants

Reaction Conditions

Reaction Steps

In the apparatus described in Example 1, 12.7 g of 4-trichloromethylbenzoic acid methyl ester (0.05 mol) and 7.5 g of 3-amino-4-hydroxybenzoic acid (0.05 mol) were mixed and heated for 6 hours at 200° C. The reaction product after grinding in a mortar was extracted twice with 100 ml of CHCl3 and then, after drying, twice with 100 ml of water. 9.2 g of raw product remained, melting at 275° to 284° C (62% of the theory). After two recrystallizations with dimethyl formamide plus active charcoal and dimethylsulfoxide, the melting point was 291° to 293° C.

Provenance & Evidence