反应详情

Using a method similar to that described by S. Paik and E. H. White (Tetrahedron, 1996, 52, 5303), 2-cyclohexylsulfamoyl-2-methylpropionic acid ethyl ester DF1 (which is prepared by the method of A. De Blic et al. (Synthesis, 1982, 281)) in ethanol is treated with 1.2 equivalent of 95% hydrazine under N2 and the mixture is allowed to stand at RT for 12 h. The reaction mixture is concentrated to give the title compound DF2 which is used directly in Step 2.

1. concentrationThe reaction mixture is concentrated