Allyl bromide → HCID 59212661, compound

Participants

Reaction Conditions

Reaction Steps

To a oven dried 5 L 4-neck round bottom flask fitted with overhead stirring, nitrogen needle, 500 mL addition funnel, 250 mL addition funnel and thermometer, tetrahydrofuran (1400 mL) and N,N,N′-trimethylethane-1,2-diamine (105 mL, 0.788 mol) were added. The solution was cooled to −40° C. (dry ice/MeCN bath). n-Butyllithium (1.6 M in hexane, 510 mL) was added to the 500 mL addition funnel and then added to the above solution over 40 minutes (−40 to −35° C.). The colorless solution became light yellow in color. The cold bath was then removed and the reaction mixture was stirred for 30 minutes while being warmed to a temperature of −10° C. The reaction was cooled to −40 to −45° C. and p-trifluoromethylbenzaldehyde (77 mL, 0.56 mol) was added via a syringe to the 250 mL addition funnel. The aldehyde was added dropwise over 15 minutes while reaction temperature was maintained at −40 to −35° C. The reaction became brown in color over the course of the addition. The reaction was stirred at −50 to −40° C. for 30 minutes. The second addition of 1.6 M of n-butyllithium in hexane (400 mL) was carried out over 50 minutes via addition funnel. The reaction mixture was allowed to warm to −25° C. and was maintained at −20 to −30° C. for 3 hours before copper(I) bromide (108 g, 0.738 mol) was added directly via a powder funnel The cold bath was removed and the reaction was allowed to warm and stirred for additional 90 minutes. The reaction was cooled to −30 to −25° C. and a solution of allyl bromide (78 mL, 0.90 mol) in tetrahydrofuran (240 mL) was added dropwise over 40 minutes through the 250 mL addition funnel in portions. After being stirred for 2 h, the reaction was quenched by the addition of methanol (100.0 mL). The cold bath was removed and the mixture was stirred for 5 minutes before 6.00 M of hydrochloric acid solution (300.0 mL) was added (pH=˜7). After the mixture was stirred for additional 15 minutes, it was passed through a celite pad, and the celite pad was rinsed with ether. Saturated ammonium chloride (400 mL) was added and the organic phase was collected. Aqueous phase was further extracted with 300 mL ether. The combined organic phase was washed with 400 ml saturated ammonium chloride (400 mL), 1 M sodium bicarbonate (3×400 mL) and brine (400 mL), and dried over magnesium sulfate. After the removal of the drying agent by filtration, the filtrate was concentrated on rotovap to give a brown liquid. Further purification was carried out by distillation to give 105.4 g (85%) of product. 1H NMR (400 MHz, CDCl3) δ (ppm) 10.22 (s, 1H), 8.02 (d, 1H), 7.80 (d, 1H), 7.74 (s, 1H), 6.02 (m, 1H), 5.06 (m, 1H), 4.96 (m, 1H), 3.89 (d, 2H).

Provenance & Evidence