NOVEL PROCESS FOR SELECTIVE ISOLATION AND PURIFICATION OF 2-[4-(4-CHLOROPHENYL) CYCLOHEXYL]-3-CHLORO-1, 4-NAPHTHOQUINONE AND ATOVAQUONE

摘要

The present invention relates to an improved method for preparation and purification of atovaquone and its intermediate product. The present invention claims for an improved method for preparation and purification of the intermediate trans-2-[4-(4-chlorophenyl)cyclohexyl]-3-chloro-1,4-naphthoquinone(II) of formula-II and also preparation of stable form of 2-[trans-4-(4-chlorophenyl)cyclohexyl]-3-hydroxy-1,4-naphthoquinone(I) Atovaquone of formula - I and selective purification of trans-2-[4-(4-chlorophenyl)cyclohexyl]-3-chloro-1,4-naphthoquinone(II) with better yield and quality.