反应详情

A solution of 2-ethoxybenzoyl chloride (6.1 g, 33.0 mmol) in dichloromethane (50 ml) was added to a stirred solution of 4-amino-1-methyl-3-n-propylpyrazole-5-carboxamide (3.0 g, 16.4 mmol), 4-dimethylaminopyridine (0.02 g, 0.164 mmol) and triethylamine (3.34 g, 33.0 mmol) in dichloromethane (50 ml) at 0° C. The resulting mixture was allowed to warm to room temperature and stirred for a further 2 hours. The solvent was evaporated under vacuum, the residue dissolved in a 19:1 mixture of dichloromethane and methanol (250 ml), and then the solution washed with 1N hydrochloric acid (100 ml), dried (MgSO4) and evaporated under vacuum. The crude material was chromatographed on silica gel (200 g), eluting with a 97:3 mixture of dichloromethane and methanol, to give a pink solid; crystallisation from ethyl acetate-hexane gave the pyrazole-5-carboxamide as a pale pink solid (2.2 g, 40%), m.p. 153°-155° C. Found: C,61.66; H,6.77; N,16.95. C17H22N4O3 requires C,61.80; H,6.71; N,16.96%.

1. customThe solvent was evaporated under vacuum
2. dissolutionthe residue dissolved in a 19:1 mixture of dichloromethane and methanol (250 ml)
3. washthe solution washed with 1N hydrochloric acid (100 ml)
4. dry with materialdried (MgSO4)
5. customevaporated under vacuum
6. customThe crude material was chromatographed on silica gel (200 g)
7. washeluting with a 97:3 mixture of dichloromethane and methanol
8. customto give a pink solid
9. customcrystallisation from ethyl acetate-hexane