反应详情

温度

-55 °C

A solution of 11.8 mL trifluoromethanesulfonic anhydride in 70 mL dichloromethane is chilled to -70° C. and treated dropwise with a solution composed of 12.6 g 1-adamantyl-2-hydroxyethane, 12.2 mL diisopropylethylamine and 70 mL dichloromethane. The solution is allowed to warm to -55° C. over 45 min then a solution of 25 g N,1-bis-BOC-histidine methyl ester (J. Chem. Soc., Perkin Trans. I 1982; 1553-61.) in 70 mL dichloromethane is added dropwise. The reaction is then stirred at 25° C. for 24 hr and poured into pH=7, 0.25M potassium phosphate buffer (500 mL), stirring vigorously. The organic layer is separated, washed with the same buffer, dried and concentrated. 3-(2-(1-Adamantyl)ethyl)-N-BOC-histidine methyl ester is isolated by chromatography on silica gel (chloroform-methanol, 99:1) as a gum. NMR (CDCl3) 3.85 (m,2H,NCH2).

1. additiontreated dropwise with a solution
2. stirringstirring vigorously
3. customThe organic layer is separated
4. washwashed with the same buffer,
5. customdried
6. concentrationconcentrated