4-Cyanobenzaldehyde → Tert-butyl 3-(4-cyanophenyl)prop-2-enoate

Participants

Reaction Steps

A flame dried three-neck flask equipped with a thermometer, an addition funnel and a N2 inlet was charged with NaH (3.96 g, 1.1 eqs) and anhydrous THF (120 mL). With moderate stirring at RT, a suspension was formed. To this suspension was added a solution of t-butyl diethylphosphonoacetate (23.2 mL 1.1 eq.) dissolved in anhydrous THF (20 mL), dropwise via the addition funnel over a period of 30 min. The suspension turned into a clear, light yellow colored solution. An exotherm from 25° C. to 35° C. was observed during the addition. After completion of the addition, the resulting mixture was stirred at RT for another 30 min. A solution of 4-cyanobenzaldehyde (11.3 g, 86.1 mmol, 1.0 eq) dissolved in anhydrous THF (20 mL) was added to the reaction mixture dropwise via the addition funnel over a period of 30 min. An exotherm from 25° C. to 35° C. was observed. The resulting mixture was stirred at RT for 1 h. Progress of the reaction was monitored by 1H NMR. Upon completion, the reaction mixture was diluted with MTBE (200 mL) and sat. NH4Cl solution (150 mL). The organic layer was separated and washed, sequentially, with 25 mL of H2O and 25 mL of sat. NH4Cl solution. After drying over MgSO4, the organic phase was evaporated to dryness to give 20.0 g 21A as a white solid (100% yield). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.56 (s, 9H) 6.47 (d, 1H) 7.53-7.64 (m, 3H) 7.68 (d, 2H)

Provenance & Evidence