反应详情

To a solution of 4.2 g (14.5 mmol) 2-(tert-butyl-dimethyl-silanyl)-imidazole-1-sulfonic acid dimethylamide in 50 ml tetrahydrofuran were added 10.9 ml (17.4 mmol) of a 1.6M butyl lithium solution in hexane at −75° C. After stirring for 20 min 3.6 g (17.4 mmol) 2,3-difluorobenzylbromide was added at −75° C. and the mixture was allowed to reach room temperature overnight. The mixture was partitioned between water and ethyl acetate, re-extracted with ethyl acetate and the combined organic layers are dried over MgSO4, filtered and evaporated. The residue was purified by flash chromatography (silica gel, hexane/ethyl acetate=4:1) to yield 3.0 g (49%) of 2-(tert-butyl-dimethyl-silanyl)-4-(2,3-difluoro-benzyl)-imidazole-1-sulfonic acid dimethylamide as a light yellow solid; MS (ISP): 416.1 ((M+H)+.).

1. additionwas added at −75° C.
2. customThe mixture was partitioned between water and ethyl acetate
3. extractionre-extracted with ethyl acetate
4. dry with materialthe combined organic layers are dried over MgSO4
5. filtrationfiltered
6. customevaporated
7. customThe residue was purified by flash chromatography (silica gel, hexane/ethyl acetate=4:1)