Aspects on the Mechanism of the 1-Phenyl-1<i>H</i>-pyrazolo[3,4-<i>b</i>]quinoxaline Formation

Condensation of D-glucose, o-phenylenediamine and N,N-benzylphenylhydrazine hydrochloride (NNBPHH) in a one-pot reaction, or condensation of 2-(D-arabino-tetritol-1-yl) quinoxaline and NNBPHH, gave 3-(D-erythro-glycerol-1- yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure of the latter was determined by 1H NMR spectroscopy and by synthesis using phenylhydrazine hydrochloride instead of NNBPHH. Condensation of D-glucose and 4,5-dichloro-o-phenylenediamine gave 6,7-dichloro-2-(D-arabino-tetritol-1-yl)quinoxaline, which upon condensation with NNBPHH gave the corresponding 6,7-dichloro-3-(D-erythro-glycerol-1-yl)-1-phenyl-1H-pyrazolo[3,4-b]quinoxaline. The structure and mechanism of formation of these compounds are discussed.

N,N-二甲氨基乙酸盐酸盐的合成研究

以氯乙酸和二甲胺水溶液为反应原料,合成了N,N-二甲氨基乙酸(DMG),加入浓盐酸得到N,N-二甲氨基乙酸盐酸盐(DMGC)晶体,并通过IR对其结构进行了表征。同时考查了原料投料比、反应温度、反应时间对反应产率的影响。实验发现较优反应条件为:二甲胺和氯乙酸的摩尔比为3∶1,反应时间10 h,反应温度为70℃,此时收率能达到80%。

微波辐射合成N,N-二甲氨基乙酸盐酸盐的研究

在微波辐射下,以氯乙酸和二甲胺为原料合成了N,N-二甲氨基乙酸盐酸盐。采用单因素实验研究了原料配比、反应温度、微波辐射功率、微波辐射时间等因素对产物收率的影响,并用红外光谱对产物进行了表征。结果表明,在n(氯乙酸)∶n(二甲胺)=1∶3.0、反应温度为65℃、微波辐射功率为500 W、微波辐射时间为150 min的优化反应条件下,N,N-二甲氨基乙酸盐酸盐的收率达86.02%。