A reinvestigation of the synthesis of Hantzsch's acid: comparison of derivatives of Hantzsch's acid with a product from the reaction of 2, 4,6-trichlorophenol and hypochlorite ion in methanol

Formation of dimer-type ketals in the reaction of 2,4,6-trichlorophenol and 2,4,6-trichloro-m-cresol with calcium hypochlorite in methanol: conversion to quinones and other compounds

2,4,6-Trichlorophenol (2) and 2,4,6-trichloro-m-cresol (5) react with calcium hypochlorite (Ca(OCl)(2)) in MeOH to give respectively dimer-type ketals 2-(2',4',6'-trichlorophenoxy)-4,4-dimethoxy-6-chlorocyclohexadien-2,5-one (6) and 2-(3'-methyl-2',4',6'-trichlorophenoxy)-4,4-dimethoxy-5-methyl-6-chlorocyclohexadien-2,5-one (7). Ketal 6, which was too unstable to be isolated, and 7 hydrolyzed in H(2)O/HCl to 2-(2',4',6'-trichlorophenoxy)-6-chloro-1,4-benzoquinone (8) and 2-(3'-methyl-2',4',6'-trichlorophenoxy)-5-methyl-6-chloro-1,4-benzoquinone (9), respectively. Ketal 6 and quinone 8 were also produced when 2 and Ca(OCl)(2) reacted in DMF, followed by addition of MeOH and H(2)O, respectively. The mechanisms of these reactions are examined. Conversion of the ketals and quinones to other products is described.