反应详情

To a solution of 2-(2-fluoro-5-methoxy-phenyl)-ethylamine (4.30 g, 25.4 mmol, 1.0 eq.) in MeOH (100 mL), glyoxal dimethyl acetal (60% aqueous solution, 5.73 g, 33.0 mmol, 1.3 eq.) was added. The resulting yellow solution was stirred at r.t. for 18 hours. The yellow solution was cooled to 0° C. and sodium borohydride (1.44 g, 38.1 mmol, 1.5 eq.) was added portionwise. The cooling bath was removed and the yellow solution was stirred at r.t. for 2 hours. The reaction mixture was concentrated in vacuo. The residue was diluted with water (50 mL) and DCM (100 mL). The layers were separated. The aq. phase was extracted with DCM (2×50 mL). The comb. org. phases were washed with water (1×150 mL), sat. aq. NaCl soln. (1×50 mL), dried over MgSO4, and concentrated in vacuo to give N-(2-fluoro-5-methoxyphenethyl)-2,2-dimethoxyethanamine. The product was used without further purification.

1. temperatureThe yellow solution was cooled to 0° C.
2. customThe cooling bath was removed
3. stirringthe yellow solution was stirred at r.t. for 2 hours
4. concentrationThe reaction mixture was concentrated in vacuo
5. additionThe residue was diluted with water (50 mL) and DCM (100 mL)
6. customThe layers were separated
7. extractionThe aq. phase was extracted with DCM (2×50 mL)
8. washphases were washed with water (1×150 mL), sat. aq. NaCl soln
9. dry with material(1×50 mL), dried over MgSO4
10. concentrationconcentrated in vacuo