反应详情

温度

0 °C

Ethyl 1-isopentyl-4-nitro-1H-pyrrole-2-carboxylate (2.377 g, 9.329 mmol; see step (i) above) was suspended in ethanol (5 mL), then a solution of NaOH (955 mg dissolved in 20 mL of water) was added. The reaction mixture was reduced by half under reduced pressure at 50° C., and then the cooled solution was extracted with ether. The water layer was cooled to 0° C. then conc. HCl was added dropwise with vigorous stirring until pH 2. The white solid material was filtered off, washed with water, dried at 60° C. under reduced pressure for 2 h then left at room temperature overnight. The product was obtained as white solid (2.008 g, 95% yield), m.p. 154-157° C. [Lit.m.p. 154-156° C.].

1. customwas reduced by half under reduced pressure at 50° C.
2. extractionthe cooled solution was extracted with ether
3. additionconc. HCl was added dropwise
4. filtrationThe white solid material was filtered off
5. washwashed with water
6. customdried at 60° C. under reduced pressure for 2 h