反应详情

To a stirred solution of 5-phenyl-thiazol-2-ylamine (0.4 g, 0.0022 mol) and DIEA (0.73 g, 0.0056 mol) in chloroform (4 mL) was added mono-ethylmalonyl chloride (0.375 g, 0.0024 mol) dropwise at 0° C. and the resulting mixture was stirred at ambient temperature for 20 minutes. The reaction mixture was then diluted with cold water and the product was extracted with chloroform. The chloroform was washed with saturated sodium bicarbonate solution and brine, dried over Na2SO4 and evaporated under reduced pressure to afford 0.3 g (46%) of N-(5-phenyl-thiazol-2-yl)-malonamic acid ethyl ester. To a solution of N-(5-phenyl-thiazol-2-yl)-malonamic acid ethyl ester (0.292 g, 0.001 mol) in the mixture of methanol (1 mL), THF (1.5 mL) and H2O (1 mL) was added LiOH.H2O (0.084 g, 0.002 mol) and the resulting mixture was stirred for 1 hour. The reaction mixture was then concentrated. The residue was diluted with water, acidified with concentrated HCl and the product was extracted with ethylacetate. The ethyl acetate was washed with brine, dried over Na2SO4 and evaporated under reduced pressure to afford 0.23 g (87%) of N-(5-phenyl-thiazol-2-yl)-malonamic acid.

1. extractionthe product was extracted with chloroform
2. washThe chloroform was washed with saturated sodium bicarbonate solution and brine
3. dry with materialdried over Na2SO4
4. customevaporated under reduced pressure