反应详情

(1-Ethylpyrazol-5-ylamino)methylenemalonate diethyl ester (180 mmol from previous reaction) was dissolved in diphenyl ether (200 mL), and the resulting solution was placed in a preheated oil bath at 255° C. The reaction solution was heated for 5 h, and then the diphenyl ether was removed via distillation. The resulting brown reaction mixture was cooled to room temperature and poured into hexane (1 L). This solution was cooled to −78° C., and the resulting precipitate was filtered to afforded the title compound as a beige colored needle shaped solid that was >90% pure by HPLC and was used directly (25 g, 60% for 2 steps). A portion was recrystallized using ethanol-H2O to afford a white solid: mp 85-86° C.; LRMS (m/z) 236 (MH+).

1. customthe resulting solution was placed in a preheated oil bath at 255° C
2. temperatureThe reaction solution was heated for 5 h
3. customthe diphenyl ether was removed via distillation
4. additionpoured into hexane (1 L)
5. temperatureThis solution was cooled to −78° C.
6. filtrationthe resulting precipitate was filtered