反应详情

32.9 G. (146 mmoles) of 2(2-n-Butoxyethoxy)-ethyl chloroformate is added dropwise to a stirred suspension of 24.9 g. (124 mmoles) of 2-(4-thiazolyl)-benzimidazole in 200 ml. of pyridine. The addition is complete in 40 minutes whereupon all of the starting material had dissolved. The reaction mixture is stirred for 16 hours at room temperature and filtered to remove pyridine hydrochloride which is washed with additional pyridine. The combined filtrate and washing are evaporated to dryness in vacuo affording a residual oil which is triturated with 300 ml. portions of ice water. The water is decanted and the residue extracted with 300 ml. of methylene chloride, filtered and the methylene chloride filtrates washed with 300 ml. of ice water, 250 ml. of 0.25 N HCl containing ice and 200 ml. of saturated sodium bicarbonate solution containing 50 ml. of ice. The organic fraction is dried, filtered and evaporated to dryness in vacuo affording 51.7 g. of a residual oil. The oil is extracted with petroleum ether whereupon a dark oil remains. The petroleum ether solution is decanted and the product separates therefrom as an oil. The petroleum ether is decanted and the remaining solvent is removed in vacuo affording 17.4 g. of a light yellow residual oil. Thin layer chromatography revealed a single spot which is confirmed by elemental analysis.

1. additionThe addition
2. dissolutionwhereupon all of the starting material had dissolved
3. filtrationfiltered
4. customto remove pyridine hydrochloride which
5. washis washed with additional pyridine
6. washThe combined filtrate and washing
7. customare evaporated to dryness in vacuo
8. customaffording a residual oil which
9. customis triturated with 300 ml
10. customThe water is decanted
11. extractionthe residue extracted with 300 ml
12. filtrationof methylene chloride, filtered
13. washthe methylene chloride filtrates washed with 300 ml
14. additionof 0.25 N HCl containing ice and 200 ml
15. additionof saturated sodium bicarbonate solution containing 50 ml
16. customThe organic fraction is dried
17. filtrationfiltered
18. customevaporated to dryness in vacuo
19. customaffording 51.7 g
20. extractionThe oil is extracted with petroleum ether whereupon a dark oil
21. customThe petroleum ether solution is decanted
22. customThe petroleum ether is decanted
23. customthe remaining solvent is removed in vacuo
24. customaffording 17.4 g