Synthesis steps of 4,5 diamino 6 hydroxy 2 mercaptopyrimidine were improved on cyclocondensation of ethyl cyanoacetate with thiourea,nitrosation and reduction to obtain the product in 89% yield with high purity on ind...Synthesis steps of 4,5 diamino 6 hydroxy 2 mercaptopyrimidine were improved on cyclocondensation of ethyl cyanoacetate with thiourea,nitrosation and reduction to obtain the product in 89% yield with high purity on industrial scale.展开更多
In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4...In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.展开更多
The title compound 3 was synthesized from diethylguanidine nitrate（2） obtained from diethylamine, CaCN2 and HNO3. The mixture consisted of 0.5 mol 2, 0.55 mol acetonyl propionate, 3 g benzyltriethylammonium chloride...The title compound 3 was synthesized from diethylguanidine nitrate（2） obtained from diethylamine, CaCN2 and HNO3. The mixture consisted of 0.5 mol 2, 0.55 mol acetonyl propionate, 3 g benzyltriethylammonium chloride, and 44 g NaOH was refluxed for 4 hours to give 85 g 3, in yield 94.6%.展开更多
文摘Synthesis steps of 4,5 diamino 6 hydroxy 2 mercaptopyrimidine were improved on cyclocondensation of ethyl cyanoacetate with thiourea,nitrosation and reduction to obtain the product in 89% yield with high purity on industrial scale.
文摘In this paper, it was found that isopropylidene (1-hydroxy-3-oxo-butylidene) malonate 4 was a heat unstable compound and the one step convenient methods for preparation of 4-hydroxy-6-methyl-2-pyrone 1 and 3-carboxy-4-hydroxy-6-methyl-2-pyrone 2 in good yields were reported. Isopropylidene malonate 3、diketen and triethylamine reacted in chloroform to give 2, and in the mixture of dichloromethane and chlorobenzene to offer 1.
文摘The title compound 3 was synthesized from diethylguanidine nitrate（2） obtained from diethylamine, CaCN2 and HNO3. The mixture consisted of 0.5 mol 2, 0.55 mol acetonyl propionate, 3 g benzyltriethylammonium chloride, and 44 g NaOH was refluxed for 4 hours to give 85 g 3, in yield 94.6%.
