Iodoethane → (RS)-[4-(tert-butyl-diphenyl-silanyloxy)-2,6-difluoro-phenyl]-ethoxy-acetic acid ethyl ester
反応式
[CH2:1]([O:3][C:4](=[O:33])[CH:5]([C:7]1[C:12]([F:13])=[CH:11][C:10]([O:14][Si:15]([C:28]([CH3:31])([CH3:30])[CH3:29])([C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)[C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[CH:9][C:8]=1[F:32])[OH:6])[CH3:2].I[CH2:35][CH3:36]>C(Cl)Cl>[CH2:1]([O:3][C:4](=[O:33])[CH:5]([C:7]1[C:12]([F:13])=[CH:11][C:10]([O:14][Si:15]([C:28]([CH3:29])([CH3:31])[CH3:30])([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)[C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)=[CH:9][C:8]=1[F:32])[O:6][CH2:35][CH3:36])[CH3:2]参加物
4
実験手順
To a well stirred solution under N2 of (RS)-[4-(tert-butyl-diphenyl-silanyloxy)-2,6-difluoro-phenyl]-hydroxy-acetic acid ethyl ester (14.9 g) in Tol (100 ml) was added Ag2O (14.7 g). The mixture was heated in an oil bath at 115–120° C. and iodoethane (12.8 ml) in Tol (50 ml) was slowly added from a dropping funnel. After a total of 2 h and 4 h more iodoethane (7.7 ml each) was added. After a total of 5.5 h heating was stopped and the mixture was left to stir over night at RT. The solids were filtered away over 1 cm of dicalite and were washed with AcOEt. The solvent was evaporated to obtain 16.3 g of crude product as a yellow oil. CC (Hept/CH2Cl2 9:1 to pure CH2Cl2) afforded 10.5 (66%) of (RS)-[4-(tert-butyl-diphenyl-silanyloxy)-2,6-difluoro-phenyl]-ethoxy-acetic acid ethyl ester next to 2.6 g (17%) of recovered starting material. Colorless oil. MS 453.2 (4, [M−OEt]+), 441.1 (24, [M−tBu]+)425.2 (100, [M−COOEt]+).