Benzocaine → HCID 768187, compound

Participants

Reaction Steps

Commercial quantities of 4-(((1,3-benzodioxol-5-yl)methyl)amino)benzoic acid are generally prepared by reacting piperonal with ethyl 4-aminobenzoate in absolute ethanol in the presence of a catalytic amount of 4-toluenesulfonic acid monohydrate to give the intermediate ethyl 4-(((1,3-benzodioxol-5-yl)mehylene)amino)benzoate. The intermediate is isolated and reduced in absolute ethanol using sodium borohydrate. The resulting ethyl 4-(((1,3-benzodioxol-5-yl)methyl)amino)benzoate is not isolated, but immediately hydrolyzed with aqueous sodium hydroxide to give sodium 4-(((1,3-benzodioxol-5-yl)methyl)amino)benzoate. The salt is converted to 4-(((1,3-benzodioxol-5-yl)methyl)amino)benzoic acid with aqueous acetic acid. The above process has been used to give satisfactory yields and was used to produce a batch containing 33 kg of pharmaceutically-acceptable product.

Provenance & Evidence