反应详情

BOC-Nva-OH, liberated from 4.78 g (12 mmoles) of the DCHA salt as described in Step 1 of Example 4, and 2.6 g (13 mmoles) of H-Met-OMe.HCl are dissolved in 40 ml of chloroform, and 1.82 ml (13 mmoles) of triethylamine are added. The mixture is cooled with ice, and a solution of 2.58 g (12.5 mmoles) of DCC in 20 ml of chloroform is added under stirring. The reaction mixture is allowed to stand at 5° C. overnight, thereafter the separated DCU is filtered off. The filtrate is washed thrice with 20 ml of n hydrochloric acid, each, thrice with 20 ml of n sodium hydrocarbonate solution, each, and then with 20 ml of water, dried over anhydrous sodium sulfate, and evaporated. The oily residue is crystallized from petroleum ether, and the resulting 3.42 g of crude product is recrystallized from a mixture of ethyl acetate and petroleum ether. 3.08 g (71%) of BOC-Nva-Met-OMe are obtained; m.p.: 69°- 70° C., Rf2 =0.81, [α]D25 =-42.7° (c=1%, in methanol).

1. temperatureThe mixture is cooled with ice
2. filtrationthe separated DCU is filtered off
3. washThe filtrate is washed thrice with 20 ml of n hydrochloric acid
4. dry with materialeach, thrice with 20 ml of n sodium hydrocarbonate solution, each, and then with 20 ml of water, dried over anhydrous sodium sulfate
5. customevaporated
6. customThe oily residue is crystallized from petroleum ether
7. customthe resulting 3.42 g of crude product is recrystallized from a mixture of ethyl acetate and petroleum ether