反应详情

3.82 g (22.4 mmol) of 3-chloro-N′-hydroxybenzenecarboximidamide and 2.00 g (22.2 mmol) of (R)-lactic acid were dissolved under Ar at 0° C. in DCM (50 mL) and DMF (15 mL). After 5 min 3.4 mL (33.2 mmol) DIC and 3.50 g (25.9 mmol) HOBt were added. After 15 min the mixture was warmed to r.t. and stirred for additional 3 h, followed by filtration and washing with DCM. The filtrate was evaporated in vacuo to near dryness, taken up in EA and washed with aq. NaHCO3, followed by water and finally 2 M aq. citric acid. The EA layer was filtered over a mixture of Na2SO4 and silica. Flash chromatography (Hep/EA=4/1 to 2/1 to 1/2) gave an oil which was triturated with Et2O to yield after drying 4 g (75%) of the title compound. 1H NMR: 7.69 (t, 1 H), 7.55-7.59 (m, 1 H), 7.44-7.49 (m, 1 H), 7.36 (t, 1 H), 5.10 (s, 2 H), 4.50 (q, 1 H), 1.54 (d, 3 H)

1. filtrationfollowed by filtration
2. washwashing with DCM
3. customThe filtrate was evaporated in vacuo
4. washwashed with aq. NaHCO3
5. filtrationThe EA layer was filtered over a mixture of Na2SO4 and silica
6. customFlash chromatography (Hep/EA=4/1 to 2/1 to 1/2) gave an oil which
7. customwas triturated with Et2O
8. customto yield
9. dry with materialafter drying 4 g (75%) of the title compound