反应详情

5-Bromo nicotinic acid ethyl ester (25 g, 108 mmol) was dissolved in ethanol (500 ml) and treated with fresh sodium borohydride (25 g, 660 mmol) added portionwise over 30 min. at 20° C. Stirring was continued overnight under an argon atmosphere. Following this 1N HCl (50 ml) was added slowly (over 20 min) followed by 2N NaOH (25 ml) and H2O (75 ml) and this mixture was stirred for 2 h at ambient temperature. After evaporation of the alcohol the aqueous phase was extracted with dichloromethane (4×150 ml) and the combined extracts were washed with brine then dried with Na2SO4, filtered and evaporated. The resulting yellow oil was dissolved in a small volume of ethanol and treated with 0.93 M HCl/EtOH (62 ml, 1.2 eq.) at 4° C. over 1 h to afford, after removal of solvent and drying under high vacuum at 50° C. for 16 h, the title compound (10.9 g, 44%) as a light yellow solid. MS: m/e=186.9 (M-′).

1. additionadded portionwise over 30 min. at 20° C
2. additionwas added slowly (over 20 min)
3. stirringthis mixture was stirred for 2 h at ambient temperature
4. customAfter evaporation of the alcohol the aqueous phase
5. extractionwas extracted with dichloromethane (4×150 ml)
6. washthe combined extracts were washed with brine
7. dry with materialthen dried with Na2SO4
8. filtrationfiltered
9. customevaporated
10. dissolutionThe resulting yellow oil was dissolved in a small volume of ethanol
11. customto afford
12. customafter removal of solvent
13. customdrying under high vacuum at 50° C. for 16 h