反应 #657285

反应方程式

sulfuric acid

2-(2-chloro-4,5-dimethyl-phenyl)-N-(4-cyano-1-methoxy-piperidin-4-yl)-N-methyl-acetamide

sulfuric acid

sodium hydroxide

sulfuric acid

→

product

收率 19.5%

3-(2-Chloro-4,5-dimethyl-phenyl)-4-hydroxy-8-methoxy-1-methyl-1,8-diaza-spiro[4.5]dec-3-en-2-one

收率 19.5%

溶剂

methanol

反应条件

后处理

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITcontinued at 90° C. over another night
3. 3
   过滤the resulting precipitate filtered
4. 4
   其他dried

实验过程

To a solution of 2-(2-chloro-4,5-dimethyl-phenyl)-N-(4-cyano-1-methoxy-piperidin-4-yl)-N-methyl-acetamide (compound P4.27) (1.15 g, 3.29 mmol) in methanol (˜3 ml) at 10° C. was added concentrated sulfuric acid (0.876 ml, 16.43 mmol) dropwise and the reaction mixture was stirred at room temperature overnight. After further treatment with concentrated sulfuric acid (0.876 ml, 16.43 mmol) and stirring at 80° C. overnight, additional concentrated sulfuric acid (0.876 ml, 16.43 mmol) was added and stirring continued at 90° C. over another night. The mixture was poured on ice, neutralised carefully with 30% aqueous sodium hydroxide to pH 5-6, the resulting precipitate filtered and dried to afford a first crop of product as a beige solid (225 mg). The mother liquor was concentrated, and the residue purified by chromatography on silica gel (ethyl acetate) to further deliver 462 mg of product as a yellowish solid. Yield: 687 mg of 3-(2-chloro-4,5-dimethyl-phenyl)-4-hydroxy-8-methoxy-1-methyl-1,8-diaza-spiro[4.5]dec-3-en-2-one (title compound P2.26) as a solid, mp 191-192° C.

来源