AGRO-WASTE AS SOURCE OF FINE AND INDUSTRIAL CHEMICALS: SYNTHESIS OF 2-FORMYL-6-HYDROXYBENZOIC ACID AND 4-METHOXYISOBENZOFURAN-1,3-DIONE FROM CASHEW NUT SHELL LIQUID

Abstract

This paper reports on the synthesis of 2-formyl-6-hydroxybenzoic acid (8) and 4-methoxyisobenzofuran-1,3-dione (10) from a renewable natural material Cashew Nut Shell Liquid (CNSL) achieved in five and seven steps, respectively. Anacardic acid was isolated from CNSL, dimethoxylated into (E)-methyl 2-methoxy-6-(pentadec-8-enyl)benzoate which was subsequently hydrogenated into methyl 2-methoxy-6-pentadecylbenzoate. Benzylic bromination of the methoxyester, and dehydrobromination afforded (E)-methyl 2-methoxy-6-(pentadec-1-enyl)benzoate which upon ozonolysis gave methyl 2-formyl-6-methoxybenzoate. Oxidation and dehydration of 8 formed methoxyphthalic anhydride (10). The work reported in this paper has further demonstrated the resourcefulness of cashew nut shell liquid as a renewable natural resource for synthesis of fine and industrial chemicals

Anacardium occidentale , Cashew Nut Shell Liquid, Anacardic acid, 2-formyl-6-methoxybenzoate, methoxyphthalic anhydride