Synthesis of conjugates of 3‐hydroxy‐ and 3‐phenoxybenzoic acids

Abstract

Conjugates of 3‐hydroxy‐ 3‐methoxy‐ and the 3‐phenoxybenzoic acids, (the major metabolites of many pyrethroid pesticides) with acetyl‐ and benzoylornithine were synthesized by means of succinimidyl ester method or N‐ethyl‐N'‐(3‐dimethylaminopropyl)carbodiimide mediated couplings. Methyl esters were removed by alkaline hydrolysis. Hydrogenolysis of N²‐substituted N⁵‐benzyloxy‐carbonylornithine methyl ester derivatives gave corresponding 3‐acylaminopiperidones. The glycylvaline methyl esters were prepared by stepwise lengthening starting with valine methyl ester using N‐ethyl‐N‘‐(3‐dimethylaminopropyl)carbodiimide as coupling reagent to introduce N‐t‐butyloxycarbonylglycine followed by coupling with the appropriate acid after the N‐t‐butyloxycarbonyl group removal.

Key words:

• Succinimidyl‐3‐hydroxybenzoate
• succinimidyl 3‐phenoxybenzoate
• succinimidyl anisate
• coupling
• N²‐substituted N⁵‐benzyloxycarbonylornithine derivatives
• hydrogenolysis
• 3‐acylaminopiperidones
• N‐t‐butyloxycarbonyl‐glycylvaline benzyl ester
• anisylglycylvaline methyl ester