Abstract

A MODIFIED APPROACH FOR THE SYNTHESIS OF 2- CYCLOHEXYL-3-HYDROXY-1,4-NAPHTHOQUINONE (PARVAQUONE), ACCOMPLISHED WITH SYSTEMATIC PROCESS DEVELOPMENT STUDIES FOR SCALABILITY

Sanjay S. S.* and Shridhara K.

Abstract

In this work, a commercially affordable key starting material 2,3- dichloro-1,4-naphthoquinone 1 has been used for the synthesis of Parvaquone 2b with relatively better yield and purity. This raw material is readily available and can efficiently displace the costly raw material 2-chloro-1,4-naphthoquinone 6, which was predominantly used in the previous synthesis. This is novel and hither to unknown synthesis. The primary starting material cyclohexyl carboxylic acid 2 was reacted with 1 to generate 2a, which on hydrolysis resulted in the formation of 2b. The reaction conditions have been optimized, thus the present modified process can be easily scaled up and commercialized.

Keywords: Parvaquone, Synthesis, Decarboxylation, Cyclohexylation, Hydrolysis, and Recovery.