反应详情

A 20 mL microwave vial was charged with 1H-pyrazole-4-carboxylic acid ethyl ester (1 g, 7.1 mmol), (R)-1-phenylethanol (1.31 mL, 10.7 mmol), triphenylphosphine (3 g, 11.4 mmol) and tetrahydrofuran (15 mL). The reaction was stirred at ambient temperature for 10 minutes before adding diisopropyl azodicarboxylate (2.25 mL, 11.14 mmol) with cooling. The vial was heated under microwave irradiation at 140° C. for 15 mins. After cooling, the solvent was removed in vacuo and the residue purified by flash chromatography on SiO2 with hexane—30% ethyl acetate/hexane (gradient) to afford intermediate (6f), 1((S)-1-Phenyl-ethyl)-1H-pyrazole-4-carboxylic acid ethyl ester as an oil, 1.646 g, 94%.

1. temperaturewith cooling
2. temperatureThe vial was heated under microwave irradiation at 140° C. for 15 mins
3. temperatureAfter cooling
4. customthe solvent was removed in vacuo
5. customthe residue purified by flash chromatography on SiO2 with hexane—30% ethyl acetate/hexane (gradient)