| abstract |
The present invention relates to a process for the preparation of (R) -methyl-2- (3-aminopiperidin- 1 -yl) -3- (2-cyanobenzyl) -4-carbonyl- 2-d] pyrimidine-6-carboxylic acid maleate ((R) -Methyl-2- (3-aminopiperidin-1-yl) -3- (2-cyanobenzyl) -4-carbonyl-3,4-dihydrothiophene [3,2-d] pyrimidine-6-carboxylic acid maleate, and a process for producing the same, wherein the crystalline form is a high-stability and low-hygroscopic crystal, and the crystalline form is a crystalline form A, Is selected. In addition, the crystalline form of the present invention has a relatively strong in-body sugar-lowering activity and can be used in the production of novel drugs for the treatment or prevention of complications of type II diabetes and / or type II diabetes. |