Synthesis of 1,2-naphthoquinone 1-oxime O-sulfate and its solvolytic properties with or without bivalent copper.
作者:KINZO NAGASAWA、KUNIKO IWAI、SHIGEKO NISHIMURA
DOI:10.1248/cpb.25.1330
日期:——
1, 2-Naphthoquinone 1-oxime O-sulfate (1) was synthesized by sulfation of 1-nitroso-2-naphthol with chlorosulfonic acid and N, N-dimethylaniline. The sodium salt of 1 was decomposed to form inorganic sulfate and 1-nitroso-2-naphthol in neutral (pH 4.9, 80°) and acidic (0.1N HCl, 40°) conditions, with their half-lives of 380 and 140 min, respectively. In an alkaline medium (0.1N NaOH, 20°), the salt was instantaneously decomposed to give a quantitative amount of inorganic sulfate and a ring-cleaved product of 1, 2-naphthoquinone 1-oxime moiety, and this product was identified as o-cyano-cis-cinnamic acid (2). The effect of Cu (II) on the hydrolysis of 1 was more accelerative in a neutral condition than in an acidic condition, resulting in the reduction of its half-life to 60 min. It was also observed that polar organic solvents such as pyridine, dioxan, and tetrahydrofuran markedly accelerated the hydrolysis of the triethylammonium salt of 1, in both neutral and acidic conditions. Reactivity of the triethylammonium and the pyridinium salts of 1 in trans-sulfation was examined in Me2SO·pyridine (4 : 1), with or without Cu (II). As estimated by the formation of sulfated products from riboflavin, 1 had a much smaller reactivity than 8-quinolyl sulfate reported previously, although the effect of Cu (II) was accelerative on the reaction.
1,2-萘醌1-肟O-硫酸酯(1)是通过用氯磺酸和N,N-二甲基苯胺对1-亚硝基-2-萘醇进行硫酸化合成的。化合物1的钠盐在中性(pH 4.9,80°)和酸性(0.1N HCl,40°)条件下分解生成无机硫酸盐和1-亚硝基-2-萘醇,其半衰期分别为380分钟和140分钟。在碱性介质(0.1N NaOH,20°)中,该盐被瞬时分解,生成定量的无机硫酸盐和1的环裂解产物1,2-萘醌1-肟单元,该产物被鉴定为o-氰基-顺式肉桂酸(2)。Cu (II)对1的水解作用在中性条件下比在酸性条件下更具加速作用,使其半衰期缩短至60分钟。还观察到,极性有机溶剂如吡啶、二噁烷和四氢呋喃在中性和酸性条件下显著加速了1的三乙铵盐的水解。在Me2SO·吡啶(4 : 1)中检查了三乙铵盐和吡啶盐在反硫酸化反应中的反应性,未加Cu (II)和加Cu (II)的效果都进行了比较。根据从核黄素形成的硫酸化产物的估算,1的反应性远小于之前报道的8-喹啉磺酸盐,尽管Cu (II)对反应有加速作用。