Studies in the cyanine dye series II Carbocyanines with substituents in the three-carbon chain
Studies in the cyanine dye series II Carbocyanines with substituents in the three-carbon chain
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DOI：
10.1021/ja01315a049
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发表时间：
1935-07-01
影响因子：
15
通讯作者：
White, FL
中科院分区：
文献类型：
--
作者：
Brooker, LGS;White, FL
讨论以水、甲醇、乙醇、二氧六环和苯为反应介质，水最适合于亚当斯催化剂，而Raney催化剂则令人满意。甲醇与阮内镍（23 ml.的氢气/分钟），产率为45%。较高的压力使亚当斯催化剂的吸附速率增加，但对阮内催化剂没有太大影响。亚硝基胍的产率无明显影响。最佳吸附温度为25-35 ℃，温度每降低或升高10 ℃，氢吸附率降低40- 70%。亚当斯催化剂对亚硝基胍的产率没有影响，但雷尼镍催化剂使产率明显降低。在Raney镍催化剂上，发现催化剂与硝基胍的最佳质量比为0.5g。每克硝基胍的催化剂。较小的比率降低氢的吸附速率，而比率为1给出最大速率，但同时亚硝基胍的产率大大降低。硝基胍催化加氢反应的进一步还原，其它催化剂的作用，硝基氨基胍、烷基硝基胍和硝基脲的还原等，是目前研究较全面的课题。
DiscussionWater, methanol, ethanol, dioxane and benzene were used as reaction media and water was found to be the most suitable for the Adams catalyst and satisfactory for the Raney catalyst. Methanol gave somewhat higher adsorption rates with Raney nickel (23 ml. of hydrogen per minute) and yields of 45% were obtained con-sistently. Higher pressures gave increased ad-sorption rates for the Adams catalyst but were without much effect for the Raney catalyst. The yields of nitrosoguanidine were not affected markedly. The optimum temperature is 25-35 and a decrease or increase of 10 resulted in a lowering of the rate of hydrogen adsorption of 40-70%. The yields of nitrosoguanidine were not affected with the Adams catalyst but with the Raney nickel the yields were materially decreased. With the Raney nickel catalyst it was found that the optimum ratio of catalyst mass to nitro-guanidine was 0.5 g. of catalyst per gram of nitroguanidine. A smaller ratio decreases the rate of adsorption of hydrogen while a ratio of 1 gives a maximum rate but at the same time the yields of nitrosoguanidine are very greatly lowered. A more comprehensive study of the catalytic hydrogenation of nitroguanidine, now in prog-ress, will include the further reductionto aminoguanidine, the effect of other catalysts and the reduction of nitroaminoguanidine, alkylnitro-guanidines and nitrourea.