تفاعل #485094

معادلة التفاعل

NaOH

5-Bromo nicotinic acid ethyl ester

sodium borohydride

HCl EtOH

HCl

→

(5-Bromo-pyridin-3-yl)-methanol Hydrochloride

المذيبات

H2O

ethanol

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONadded portionwise over 30 min. at 20° C
2. 2
   workup.ADDITIONwas added slowly (over 20 min)
3. 3
   workup.STIRRINGthis mixture was stirred for 2 h at ambient temperature
4. 4
   أخرىAfter evaporation of the alcohol the aqueous phase
5. 5
   استخلاصwas extracted with dichloromethane (4×150 ml)
6. 6
   غسيلthe combined extracts were washed with brine
7. 7
   تجفيفthen dried with Na2SO4
8. 8
   ترشيحfiltered
9. 9
   أخرىevaporated
10. 10
    workup.DISSOLUTIONThe resulting yellow oil was dissolved in a small volume of ethanol
11. 11
    أخرىto afford
12. 12
    أخرىafter removal of solvent
13. 13
    أخرىdrying under high vacuum at 50° C. for 16 h

الإجراء التجريبي

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-′).

المصدر