反应详情

Bromine (2.5 mL, 46.1 mmol) was added to a solution of Example J5, benzyl 4-(4-bromophenyl)-4-oxobutanoate (16 g, 46.1 mmol) in ether (200 mL) and 1,4-Dioxane (50 mL) and the solution was stirred for 6 hours before being concentrated by rotory evaporation and taken up in acetonitrile (450 mL). Sodium azide (3.0 g, 46.1 mmol) was added and the reaction mixture stirred 18 hours. The solvent was removed upon concentration and the residue taken up in ethyl acetate and wash with water, brine, dried Na2SO4, and filtered. Concentration gave benzyl 3-azido-4-(4-bromophenyl)-4-oxobutanoate 17 g (95%) which was carried forward without further purification. Tin (II) chloride dehydrate (24.9 g, 131 mmol) was added to a solution of benzyl 3-azido-4-(4-bromophenyl)-4-oxobutanoate (17 g, 43.8 mmol) in CH3OH (550 mL) and stirred for 14 hours at 65° C. The reaction was concentrated by rotory evaporation and dried under high vacuum for 18 hours to give a mixture of benzyl and Example J6, methyl 3-amino-4-(4-bromophenyl)-4-oxobutanoate, (transesterification had occurred) and carried forward with purification. RT=1.3 minutes (condition 1); LCMS: Anal. C11H12BrNO3 Calcd. 286.0. found: 286.14 (M+H)+.

1. concentrationbefore being concentrated by rotory evaporation
2. stirringthe reaction mixture stirred 18 hours
3. customThe solvent was removed upon concentration
4. washwash with water, brine, dried Na2SO4
5. filtrationfiltered
6. concentrationConcentration