Water → Ethyl diethoxymethyl(benzyl)phosphinate

Participants

Reaction Steps

A suspension of 16.5 g of sodium hydride (80% in oil) in 100 ml of anhydrous tetrahydrofuran under an inert atmosphere at 20° is treated with 100 ml of an anhydrous tetrahydrofuran solution of 104.4 g of ethyl (diethoxymethyl)phosphinate at such a rate so that the temperature does not exceed 25°. After the addition is complete, the resulting suspension is stirred for 1 hour at room temperature. This suspension is then treated with 85.5 g of benzylbromide and the reaction mixture stirred overnight at room temperature. The reaction mixture is then cooled in an ice/water bath and 200 ml of water are carefully added. The clear solution is then partitioned between dichloromethane and water. Separation of the dichloromethane layer followed by drying and removal of the solvent affords a pale yellow oil. Distillation in high vacuum affords ethyl-P-benzyl-P-diethoxymethylphosphinate of b.p. 105°-125° (10-2 mbar); 1H-NMR (CDCl3): δ (ppm)=7.29 (5H, m, Ph), 4.58 (1H, d, J= 9 Hz, CHP), 4.08 (2H, q, CH2OP), 3.83 and 3.66 (4H, m, 2×CH2OC), 3.21 (2H, ABqJ=15×6.0 Hz, CH2Ph), 1.23 (9H, m, 3×CH3).

Provenance & Evidence