Dichloromethane → 7-Bromo-2-[(R)-1-(tert-butyl-dimethyl-silanyloxy)-ethyl]-quinoline

Participants

Reaction Steps

A solution of (R)-1-(7-bromo-quinolin-2-yl)-ethanol (2.52 g, 10 mmol) in dichloromethane (55 mL) was cooled to 0° C. before adding trimethylsilyl trifluoromethanesulfonate (2.7 mL, 12 mmol) and 2,6-lutidine (1.75 mL, 15 mmol). The reaction mixture was stirred for 2 h then treated with a saturated solution of potassium phosphate monobasic in water. The aqueous layer was extracted with dichloromethane. The extracts were combined, dried over anhydrous magnesium sulfate and the volatiles were evaporated. A second batch was made in the same way from (R)-1-(7-bromo-quinolin-2-yl)-ethanol (375 mg, 1.49 mmol) using the same proportions of reagents. After the same work up the crudes were combined, and purified by silica gel chromatography using a stepwise gradient of iso-hexanes/ethyl acetate 99:1 to 24:1 to yield the title product (3.96 g, 94%) as a solid. 1H NMR (300 MHz, CDCl3) δ 0.02 (s, 3H), 0.12 (s, 3H), 0.94 (s, 9H), 1.54 (d, J=6.5 Hz, 3H), 5.12 (q, J=6.5 Hz, 1H), 7.61 (dd, J=8.7, 1.8 Hz, 1H), 7.69 (d, J=8.5 Hz, 1H), 7.75 (d, J=8.5 Hz, 1H), 8.15 (d, J=8.5 Hz, 1H), 8.24 (s, 1H).

Provenance & Evidence