The treatment of chloranil (I) with alkali and 2-mercaptoethanol resulted not only in replacement of the chlorine atoms but also in reduction to form 2,3,5,6-tetrakis(β-hydroxyethylmercapto)-1,4-hydroquinone (II). The conditions for the preparation of 2,3,5,6-tetrakis(β-chloroethylmercapto)-1,4-hydroquinone (III) from II differed from those required for the preparation of a lower-melting compound (IV) from II by such a narrow margin that exact control of temperature and concentration were necessary in order to avoid erratic behavior in the preparation. The structure of the lower-melting compound has been established as 2,3-dihydro-5,7,8-tris(β-chloroethylmercapto)-6-hydroxy-1,4-benzoxathiin (IV) by analyses and cyclization reactions. The treatment of 2,3-dichloro-1,4-naphthoquinone (VIII) with 2-mercaptoethanol yielded 2,3-bis(β-hydroxyethylmercapto)-1,4-naphthoquinone (IX) and not the quinol as was the case with chloranil. The quinone (IX) could not be converted to 2,3-bis(β-chloroethylmercapto)-1,4-naphthoquinone by treatment with hydrogen chloride because under these conditions only 1,4-oxathio-5,10-anthraquinone (X) was formed. A mechanism for the formation of X which involves intramolecular addition, elimination, and cyclization is described.
氯醌(I)与碱和2-巯基乙醇的处理不仅导致氯原子的取代,还导致还原形成2,3,5,6-四(β-羟乙基巯基)-1,4-氢醌(II)。从II制备2,3,5,6-四(β-氯乙基巯基)-1,4-氢醌(III)的条件与从II制备较低熔点化合物(IV)的条件有所不同,需要精确控制温度和浓度,以避免制备过程中的不稳定行为。通过分析和环化反应,已确定较低熔点化合物的结构为2,3-二氢-5,7,8-三(β-氯乙基巯基)-6-羟基-1,4-苯并噻嗪(IV)。将2,3-二氯-1,4-萘醌(VIII)与2-巯基乙醇处理得到2,3-双(β-羟乙基巯基)-1,4-萘醌(IX),而不像氯醌那样生成醌醇。醌(IX)无法通过氯化氢处理转化为2,3-双(β-氯乙基巯基)-1,4-萘醌,因为在这些条件下只形成了1,4-氧硫-5,10-蒽醌(X)。描述了涉及分子内加成、消除和环化的X形成机制。