反应详情

To a 0° C. solution of dipeptide 5 (2.18 g, 5.11 mmol) in methanol (30 mL) was slowly added excess thionyl chloride (1.9 mL). The solution stirred at ambient temperature for 2.5 h. The solvent was evaporated and the residue was triturated with ˜30 mL of ether, producing a white solid that was collected by filtration. The solid was dissolved in methanol (40 mL) and treated with ammonium hydroxide (29%, 10 mL) and then stirred for 18 h followed by concentration. The solid residue was partitioned between saturated NaHCO3 (40 mL), water (20 mL) and CHCl3:isopropyl alcohol, 4:1 (40 mL). The organic phase was separated and the aqueous phase extracted with CHCl3:isopropyl alcohol, 4:1 (3×40 mL). The combined organic phases were dried (K2CO3) and concentrated to afford 6 as a white solid (1.382 g, 92% yield). 1H NMR (400 MHz, CDCl3): δ 2.99 (d, part of AB pattern, J=17.6 Hz, 1H), 3.17 (m, AB pattern, 2H), 3.52 (d, part of AB pattern, J=17.6 Hz, 1H), 4.35 (m, 1H), 4.48 (m, AB pattern, J=14.7 Hz, 1H), 6.39 (bs, NH, 1H), 7.13-7.35 (m, 10H, overlapped with CDCl3); 13C NMR (100 MHz, CDCl3): δ 40.5, 48.2, 49.6, 56.4, 127.4, 128.1, 128.59, 128.63, 128.8, 130.0, 134.65, 134.68, 165.2, 166.3.

1. customTo a 0° C.
2. customThe solvent was evaporated
3. customthe residue was triturated with ˜30 mL of ether
4. customproducing a white solid
5. filtrationthat was collected by filtration
6. dissolutionThe solid was dissolved in methanol (40 mL)
7. additiontreated with ammonium hydroxide (29%, 10 mL)
8. stirringstirred for 18 h
9. concentrationfollowed by concentration
10. customThe solid residue was partitioned between saturated NaHCO3 (40 mL), water (20 mL) and CHCl3
11. customThe organic phase was separated
12. extractionthe aqueous phase extracted with CHCl3
13. dry with materialThe combined organic phases were dried (K2CO3)
14. concentrationconcentrated