反应详情

A mixture of 2,4-diketo-4-(thiazol-2-yl)butyric acid ethyl ester (9.88 g), hydrazine hydrate (1.74 g), and ethanol (25 ml) was refluxed for one hour, concentrated and the residue chromatographed (silica gel, EtOAc/Hex 1/2) to afford 2.58 g of 5-(thiazol-2-yl)pyrazole-3-carboxylic acid ethyl ester. NMR: 1.42 (t, 3H), 4.44 (q, 2H), 7.37 (s, 1H, 4-pyrazolyl H), 7.40, 7.75 (2d, 2H, thiazolyl H's).

1. temperaturewas refluxed for one hour
2. concentrationconcentrated
3. customthe residue chromatographed (silica gel, EtOAc/Hex 1/2)