反应详情

17.9 G (0.108 moles) of 2-ethyl-1-butyl chloroformate is added dropwise with protection from moisture to a stirred suspension of 21.7 (0.108 moles) of 2-(4-thiazolyl)-benzimidazole in 150 ml. of pyridine. The addition is carried out over a period of 35 minutes after which the reaction mixture is stirred overnight at room temperature. The reaction mixture is filtered and the filtrate evaporated to dryness in vacuo. The gummy residue is treated with 250 ml. of methylene chloride, filtered and washed twice with 250 ml. of 0.25 N-hydrochloric acid containing ice and 200 ml. of saturated sodium bicarbonate solution. The methylene chloride is dried and evaporated to dryness in vacuo affording 23.8 g. (67%) of a yellow-orange residual oil which is purified by column chromatography, the extract of which thin layer chromatography demonstrates to be pure 1-(2-ethyl-1-butoxycarbonyl)-2-(4-thiazolyl)-benzimidazole.

1. additionThe addition
2. filtrationThe reaction mixture is filtered
3. customthe filtrate evaporated to dryness in vacuo
4. additionThe gummy residue is treated with 250 ml
5. filtrationof methylene chloride, filtered
6. washwashed twice with 250 ml
7. additionof 0.25 N-hydrochloric acid containing ice and 200 ml
8. dry with materialThe methylene chloride is dried
9. customevaporated to dryness in vacuo
10. customaffording 23.8 g
11. custom(67%) of a yellow-orange residual oil which is purified by column chromatography
12. extractionthe extract of which thin layer chromatography