反应详情

温度

-23 °C

The resultant compound from Example 13g (2.23 g, 4.87 mmol) was stirred for 1 h in 4.5M ethanolic HCl (15 ml). The solvent was evaporated with ether and toluene chasers and the residue was dissolved in dimethylformamide (25 ml) and treated with Boc-His-OH (1.37 g, 5.36 mmol) and 1-hydroxybenzotriazole (1.98 g, 14.6 mmol). The mixture was cooled to -23° C. and N-methylmorpholine (600 microliters, 5.46 mmol) was added followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (1.05 g, 5.46 mmol). The mixture was stirred at -23° C. for 2 h and at room temperature 16 h, and then was poured into saturated NaHCO3 solution and extracted into ethyl acetate which was washed with water and brine, then dried over Na2SO4 and evaporated. Chromatography of the residue on silica gel with 4% methanol in chloroform provided 1.785 g (72%) of the desired product as a white solid. 1H-NMR (CDCl3, TMS) delta 7.58 (s,1H), 6.89 (s,1H), 6.26 (m,1H), 4.39 (m,1H), 4.13 (m, 1H), 4.40 (m,1H), 3.30 (m,2H), 3.16 (dd,1H , 3.01 (dd,1H), 1.47 (s,9H), 1.17 (t,3H).

1. customThe solvent was evaporated with ether and toluene chasers
2. dissolutionthe residue was dissolved in dimethylformamide (25 ml)
3. extractionextracted into ethyl acetate which
4. washwas washed with water and brine
5. dry with materialdried over Na2SO4
6. customevaporated