反应详情

Stir a mixture of methyl 2-bromo-N-(methoxycarbonyl)-D-phenylalaninate (29.1 g, 92.10 mmol) and paraformaldehyde (9.13 g, 101.3 mmol) in glacial acetic acid (115 mL, 2.01 mol) and concentrated sulfuric acid (38.4 mL, 719.9 mmol) at room temperature for 7 hours. Partition between water and ethyl acetate. Separate the layers and extract the aqueous layer with ethyl acetate. Combine the ethyl acetate extracts and dry over sodium sulfate, filter, and concentrate under reduced pressure. Purify the residue by silica gel chromatography eluting with ethyl acetate: hexanes (5-40% gradient) to give the title compound (27.6 g, 84.0 mmol). MS (m/z): 328 (M+1).

1. customPartition between water and ethyl acetate
2. customSeparate the layers
3. extractionextract the aqueous layer with ethyl acetate
4. dry with materialdry over sodium sulfate
5. filtrationfilter
6. concentrationconcentrate under reduced pressure
7. customPurify the residue by silica gel chromatography
8. washeluting with ethyl acetate