反应详情

1N Sodium hydroxide (12.9 ml., 3.8 equiv.) is added dropwise over 10 minutes to a chilled solution (ice bath) of the product from part (b) (1.20 g., 3.41 mmole) dissolved in methanol (13 ml.) under a nitrogen atmosphere. The mixture is stirred at 0° for 10 minutes and then allowed to warm to room temperature and stirred for 3 hours. The mixture is concentrated to half volume in vacuo. The residue is diluted with water (40 ml.) washed with chloroform (2×20 ml.), and acidified to a pH of about 1.5 with concentrated hydrochloric acid. The resulting white suspension is extracted with ethyl acetate (3×15 ml.). These organic extracts are combined, washed with water and brine (20 ml. each), dried (Na2SO4) and concentrated to yield a white waxy solid (0.82 g.). This solid is dissolved in ethyl acetate, filtered, concentrated and the residue triturated with ether to give (±)-5-[[2-(mercaptomethyl)-1-oxo-3-phenylpropyl]amino] pentanoic acid as white solids; m.p. 78°-79°. TLC (silica gel, 4:1 benzene/acetic acid) Rf =0.30 (slight tailing).

1. stirringstirred for 3 hours
2. concentrationThe mixture is concentrated to half volume in vacuo
3. additionThe residue is diluted with water (40 ml.)
4. washwashed with chloroform (2×20 ml.)
5. extractionThe resulting white suspension is extracted with ethyl acetate (3×15 ml.)
6. washwashed with water and brine (20 ml
7. dry with materialeach), dried (Na2SO4)
8. concentrationconcentrated
9. customto yield a white waxy solid (0.82 g.)
10. filtrationfiltered
11. concentrationconcentrated
12. customthe residue triturated with ether