Hydrohalogenation of N-[arylsulfonylimino(phenyl)methyl]-1,4-benzoquinone monoimines having alkyl substituents in the quinoid ring

Abstract

Hydrohalogenation of N-[arylsulfonylimino(phenyl)methyl]-2,5(3,5)-dimethyl-1,4-benzoquinone monoimines follows exclusively the 1,4-addition pattern, whereas N-[arylsulfonylimino(phenyl)methyl]-2,6-dimethyl-1,4-benzoquinone monoimines take up hydrogen halides according to the 6,3-addition scheme. Ar = Ph (a), 4-MeC 6 H 4 (b), 4-ClC 6 H 4 (c); I, IV, VII, X, XIII, R 1 = R 2 = Me; II, V, VIII, XI, XIV, R 1 = i-Pr, R 2 = Me; III, VI, IX, XII, XV, R 1 = Me, R 2 = i-Pr; IV-VI, X-XII, Hlg = Cl; VII-IX, XIII-XV, Hlg = Br.