反应详情

To a solution of [(S)-1,4-dimethyl-4-(3-nitro-phenyl)-6-oxo-1,4,5,6-tetrahydro-pyrimidin-2-yl]-carbamic acid tert-butyl ester (110 mg, intermediate E1) in THF (3.0 ml) was added at −78° C. a solution of LDA (3 eq., 1.95 ml) and stirring was continued for 1 h. The mixture was treated at −78° C. with a solution of iodomethane (38 μl) in THF (2.0 ml) and stirring was continued at the same temperature for 1.5 h. The mixture was quenched with saturated aqueous NH4Cl, extracted with diethyl ether, the organic layer was dried and evaporated. The residue was chromatographed on silica using n-heptane/ethyl acetate (5:1) to give [(4S,5R)-1,4,5-trimethyl-4-(3-nitro-phenyl)-6-oxo-1,4,5,6-tetrahydro-pyrimidin-2-yl]-carbamic acid tert-butyl ester (72 mg) as a colorless foam. MS (ESI): m/z=377.4 [ M+H]+. The hydrogenation of the nitro group to give the aniline (intermediate F) was carried out as described in Scheme 1.

1. stirringstirring
2. waitwas continued at the same temperature for 1.5 h
3. customThe mixture was quenched with saturated aqueous NH4Cl
4. extractionextracted with diethyl ether
5. customthe organic layer was dried
6. customevaporated
7. customThe residue was chromatographed on silica