Halogenation of n-substituted p-quinone monoimines and p-quinone monooxime esters: VIII. Halogenation of N-aroyl(arylsulfonyl)-2,6-di-tert-butyl-1,4-benzoquinone monoimines and their reduced forms

Chlorination of N -aroyl(arylsulfonyl)-2,6-di- tert -butyl-1,4-benzoquinone imines gave Z and E isomers of 4-arylsulfonylimino-2,6-di- tert -butyl-5,6-dichlorocyclohex-2-en-1-ones and Z isomers of 4-aroyl-(arylsulfonyl)imino-2,6-di- tert -butyl-5,5,6-trichlorocyclohex-2-en-1-ones, in which the tert -butyl group on the sp 3 -hybridized carbon atom occupies exclusively the axial position. The formation of Z / E -isomeric structures is related to configurational stability of the chlorination products. The chlorination of 4-aroylamino-2,6-di- tert butylphenols was found to be accompanied by replacement of one tert -butyl group by chlorine atom with formation of 4-aroylimino-6- tert -butyl-2,3,5,6-tetrachlorocyclohex-2-en-1-ones.