Iodoethane → (RS)-[4-(tert-butyl-diphenyl-silanyloxy)-2,6-difluoro-phenyl]-ethoxy-acetic acid ethyl ester

Participants

Reaction Steps

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]+).

Provenance & Evidence