Preparation of Diethyl 3,5-Dimethyl-1H-pyrrole-2,4-dicarboxylic Acid
A mixture of 200 g (1.54 mol) of ethyl acetoacetic ester in 450 ml of acetic acid was cooled in an icemethanol bath,
stirred, and a solution of 54 g (0.78 mol) of sodium nitrite in 100 ml of water was added (dropwise).
The solution was stirred at 0.deg. C. for an additional 2.5 hours and then allowed to come to room temperature.
Zinc dust (100 g) was added to the mixture in portions which caused the mixture to boil.
The mixture was heated to the reflux temperature for 1.5 hours and poured into 3 liters water.
The product crystallized, was collected, and then washed with water.
Recrystallization from ethanol gave 85 g of solid title compound, m.p. 135.deg.-136.deg. C,
Preparation of Diethyl 3,5-Dimethyl-1H-pyrrole-2,4-dicarboxylic Acid
A mixture of 200 g (1.54 mol) of ethyl acetoacetic ester in 450 ml of acetic acid was cooled in an icemethanol bath,
stirred, and a solution of 54 g (0.78 mol) of sodium nitrite in 100 ml of water was added (dropwise).
The solution was stirred at 0.deg. C. for an additional 2.5 hours and then allowed to come to room temperature.
Zinc dust (100 g) was added to the mixture in portions which caused the mixture to boil.
The mixture was heated to the reflux temperature for 1.5 hours and poured into 3 liters water.
The product crystallized, was collected, and then washed with water.
Recrystallization from ethanol gave 85 g of solid title compound, m.p. 135.deg.-136.deg. C,
得到单乙酯,再NaOH水解得二酸.
先谢谢楼上的朋友,有没有具体的文献啊?我这样看的不太明白,有关这个物质的合成的相关文献,麻烦贴上来,我可以再去文献求助版块去求原文,谢谢啊。
这是专利atent; Merrell Dow Pharmaceuticals Inc.; US4560700; (1985); (A1) English,你看不懂英文吗?操作很详细了.英文专利的原文比这复杂多了,不好看的.要我翻译成中文!!
再次感谢楼上的朋友,不过你把我需要的化合物搞错了,你帮我搜索到的是它的二乙酯的合成和单乙酯的合成,而我需要的是二羧酸的合成,麻烦大家再帮忙找找。
老天呀! 酯水解不是羧酸吗?哪有一步做成羧酸的.
酯加NaOH 水溶液,室温反应,点板到反应完.加HCl成酸,用乙酸乙酯萃取出来就得了.
如果你真要文献的话,下面是酯水解的文献:
Micheli, Fabrizio; Fabio, Romano Di; Cavanni, Paolo; Rimland, Joseph M.; Capelli, Anna Maria; Chiamulera, Cristiano; Corsi, Mauro; Corti, Corrado; Donati, Daniele; Feriani, Aldo; Ferraguti, Francesco; et al.
Bioorganic & Medicinal Chemistry, 2003 , vol. 11, # 2 p. 171 - 184