Patent ID: 8283499

Claim:
A process for the preparation of 2-cyclohexyl-1,4-naphthoquinones compounds of Formula III and its isomers, wherein, R 3 is selected from the group consisting of C 1-6 alkoxy; aralkoxy; C 1-6 alkyl-C 1-6 alkoxy; hydrogen; unsubstituted phenyl; phenyl substituted by one or more groups, preferably selected from halogens; C 1-6 linear or branched alkyl, halogen and perhalo-C 1-6 alkyl; R 4 is selected from the group comprising consisting of hydroxyl; a group OCOR 5 , wherein R 5 is a C 1-10 alkyl group, a C 3-10 cycloalkyl group, a C 1-10 alkoxy group, or a phenyl or naphthyl group, each such R 5 group being optionally substituted e.g. by amino, mono or di-C 1-4 alkylamino, carboxy or hydroxy; a group OR 6 or SR 6 , wherein R 6 is an optionally substituted C 1-10 alkyl, C 3-10 cycloalkyl, phenyl or naphthyl group as defined for R 5 or a group NR 7 R 8 , wherein R 7 and R 8 each independently represent hydrogen or C 1-4 alkyl, or the group NR 7 R 8 which represents a 5-7 membered saturated heterocyclic ring, which may optionally contain a further heteroatom selected from nitrogen, oxygen or sulfur, comprising the steps of: (i) condensing 2,3-dihalonaphthoquinone compounds of Formula I wherein R 1 and R 2 are leaving groups selected from the group consisting of Cl, Br, I and F and the R 1 and R 2 may be the same halogen or may contain different halogen groups, or sulphonyl groups, and physiologically acceptable salts and other physiologically functional derivatives thereof, with wherein R is selected from the group consisting of H, to prepare napthoquinone compounds of Formula IA; wherein X is any aryl, heteroaryl, alkyl, cyclohexyl, substituted cylohexyl groups; (ii) treating napthoquinone compounds of Formula IA with base in a suitable solvent to form the 2-cyclohexyl-1,4-naphthoquinones compounds of Formula III.