反应详情

To a stirred solution of 400 mg of (R)-2-[2 -amino-2-(3-methyl-1,2,4-oxadiazol-5-yl)-ethylsulfanyl-methyl]-3-[dimethyl-(1,1,2-trimethyl-propyl)-silanyloxy]-5-methoxy -6-methyl-benzoic acid methyl ester in 20 ml of dry dichloromethane were added slowly 186 mg of 1,1'-thiocarbonyldi-2(1H)-pyridone. The red solution was stirred for 30 min at room temperature and then cooled in an ice bath. Upon the addition of 94 mg of benzamidine (~85%), stirring was continued for 1 h at 0° C. and for 10 h at 20° C. The solution was evaporated in vacuo and the residue was chromatographed on silica gel using ethyl acetate/hexane (2:1, v/v) as eluent to afford 480 mg of (R)-3-[dimethyl-(1,1,2-trimethyl-propyl)-silanyloxy]-2-[2-[3-(imino-phenyl-methyl)-thioureido]-2-(3-methyl-1,2,4-oxadiazol-5-yl) -ethylsulfanylmethyl]-5-methoxy-6-methyl-benzoic acid methyl ester as a colorless oil.

1. temperaturecooled in an ice bath
2. stirringstirring
3. waitwas continued for 1 h at 0° C. and for 10 h at 20° C
4. customThe solution was evaporated in vacuo
5. customthe residue was chromatographed on silica gel