反应详情

3-[2-(2-Chloro-4-methyl-thiazol-5-yl)-acetylamino]-pyrazine-2-carboxylic acid methyl ester (Example 2.2) (1.020 g) was heated to 110° C. with potassium carbonate (1.08 g) in dry N,N-dimethylformamide (30 ml) for 3 hours. The reaction mixture was allowed to cool to ambient temperature, diluted with water and the mixture extracted with ethyl acetate. The aqueous fraction was acidified to pH 3 by addition of concentrated hydrochloric acid (36% by weight in water) and then extracted again with ethyl acetate. The organic fraction was washed with water, dried over magnesium sulfate, and concentrated to give Compound No. B1 of Table B (0.61g).

1. extractionthe mixture extracted with ethyl acetate
2. additionThe aqueous fraction was acidified to pH 3 by addition of concentrated hydrochloric acid (36% by weight in water)
3. extractionextracted again with ethyl acetate
4. washThe organic fraction was washed with water
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated
7. customto give Compound No