反应详情

To a stirred and cooled (-78° C.) solution of 7.2 parts of 3-bromothiophene in 70 parts of 1,1'-oxybisethane were added 30 parts of a 1-butyllithium solution 1.6M in hexane. After stirring for 20 minutes at this low temperature, a solution of 6 parts of butyl-1H-benzotriazole-5-carboxaldehyde was added to the previous mixture. The reaction mixture was stirred for 2 hours at -78~-40° C. The whole was poured into 200 parts of ice water and the product was extracted three times with 56 parts of 1,1'-oxybisethane. The combined extracts were dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of dichloromethane and methanol (98.2 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from 2,2'-oxybispropane. The product was filtered off and dried, yielding 5 parts (58.9%) of 1-butyl-α-(3-thienyl)-1H-benzotriazole-5-methanol; mp. 80° C. (int. 58).

1. stirringAfter stirring for 20 minutes at this low temperature
2. stirringThe reaction mixture was stirred for 2 hours at -78~-40° C
3. extractionthe product was extracted three times with 56 parts of 1,1'-oxybisethane
4. customThe combined extracts were dried
5. filtrationfiltered
6. customevaporated
7. customThe residue was purified by column chromatography over silica gel using
8. additiona mixture of dichloromethane and methanol (98.2 by volume) as eluent
9. customThe pure fractions were collected
10. customthe eluent was evaporated
11. customThe residue was crystallized from 2,2'-oxybispropane
12. filtrationThe product was filtered off
13. customdried