Some Chloro Nitro Derivatives of Metacresol: Colour and Constitution of Benzene Azophenols

Abstract

Although a considerable amount of work has been done on the chloro-nitro derivatives of metacresol, the series is not yet complete, and some confusion exists as to the identity of certain members.

This is in some measure due to an alternative method of nomenclature adopted by the Americans, ho number from the hydroxyl group, instead of from the methyl group, so that with them, 6- chloro- 4- nitro-m-cresol (133°) becomes 4- chloro-6-nitro-m -cresol. Another factor causing incorrect orientation, is a tendency to displace halogen groups shown by entering nitro- groups. Robertson (T. 1912 1961) , showed that 6- chloro- thymol on nitration yielded 2- chloro-6-ni\tro thymol, as well as considerable quantities of 6-nitro- tbymol, and 2.6. dinitro- thymol.