Ethyl 5-hydrazinyl-1,3-thiazole-4-carboxylate → ethyl 5-[4-(2-methoxy-2-oxoethyl)-3-methyl-5-(pyridin-2-yl)-1H-pyrazol-1-yl]-1,3-thiazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

In a microwave reactor, 0.358 g (1.91 mmol) of ethyl 5-hydrazinyl-1,3-thiazole-4-carboxylate were added to 0.450 g (1.91 mmol) of methyl 4-oxo-3-(pyridin-2-ylcarbonyl)pentanoate in 4 ml methanol. In a microwave oven the closed vessel was heated at 90° C. for 2 hours. After removal of the solvent, the residue was extracted repeatedly with dichloromethane/water. The combined organic phases were dried over sodium sulfate and the solvent was removed under reduced pressure. Chromatography of the residue gave 0.508 g of product (61.8% of theory), NMR (CDCl3, 300 MHz): 1.12 (t, 3H); 2.35 (s, 3H); 3.66 (s, 2H); 3.69 (s, 3H); 4.08 (s, 3H); 7.19 (m, 1H); 7.32 (m, 1H); 7.66 (m, 1H); 8.51 (m, 1H); 8.72 (s, 1H).

Provenance & Evidence