反应详情

2.15 g of 3-chloro-N-(5-chloro-1H-benzimidazol-2-ylmethyl)-4-methoxycarbonylbenzamide is dissolved in 50 mL of isopropanol, and 50 mL of 1 molar sodium hydroxide solution is added and the mixture is stirred for 3 hours at ambient temperature. Then it is poured into 250 mL ice water and extracted twice with ethyl acetate. The aqueous phase is adjusted to pH 4 with 1 molar hydrochloric acid and the precipitate formed is separated off by filtration. The solid is washed with a little demineralized water and dried at 40° C. Then the solid obtained is treated with 150 mL of solvent mixture comprising petroleum ether/diethyl ether/ethyl acetate and dried again. Yield: quantitative; C16H11Cl2N3O3 (364.19); mass spectrum: (M+H)+=364/66/68 (chlorine isotope).

1. extractionextracted twice with ethyl acetate
2. customthe precipitate formed
3. customis separated off by filtration
4. washThe solid is washed with a little demineralized water
5. customdried at 40° C
6. customThen the solid obtained
7. customdried again