Tetrahydrofuran → trans t-Butyl 2-(4-bromophenyl)cyclopropane carboxylate

Participants

Reaction Steps

The trans t-butyl 3-(4-bromophenyl)acrylate was prepared as follows: A flame dried three-neck flask equipped with a thermometer, an addition funnel and a N2 inlet was charged with NaH (3.96 g, 99.1 mmol, 1.1 eq.) and anhydrous THF (120 mL). With moderate stirring under N2, a solution of t-butyl diethylphosphonoacetate (23.2 mL, 99.1 mmol, 1.1 eq.) dissolved in anhydrous THF (20 mL) was charged dropwise via addition funnel over a period of 30 min. The resulting mixture changed from a slurry to a clear, light yellow colored solution. An exotherm from 25° C. to 35° C. was observed during the addition. After completing the addition, the solution was stirred at RT for 30 min. A solution of 4-bromobenzaldehyde (15.9 g, 86.1 mmol, 1.0 eq) dissolved in anhydrous THF (20 mL) was charged to the above solution dropwise via the addition funnel over a period of 30 min. An exotherm from 25° C. to 35° C. was observed. The reaction mixture was stirred at RT for 1 h. The reaction mixture was analyzed for completion using 1H NMR. The reaction mixture was diluted by the sequential addition of MTBE (200 mL) and sat. NH4Cl (150 mL). The organic layer was separated and washed with H2O (25 mL), and sat. NH4Cl (25 mL). After drying over MgSO4, the organic layer was evaporated to dryness to give 23.7 g desired product as a white solid (97.5% yield). 1H NMR (400 MHz, CDCl3-d) δ ppm 1.55 (s, 9H) 6.38 (d, 1H) 7.39 (d, 2H) 7.45-7.59 (m, 3H).

Provenance & Evidence