Sodium Hydroxide → 1-Phenyl-3,4-dihydroisoquinoline

Participants

Reaction Steps

75.5 g (532 mmol, 1.2 eq.) of P2O5 are added with stirring to a solution of 100.0 g (446 mmol) of N-(2-phenylethyl)benzamide in 375 ml of xylene. 124.1 ml (1.34 mol, 3.0 eq.) of PPCl3 are subsequently added, and the reaction mixture is refluxed with TLC monitoring. When the conversion is complete, the reaction solution is poured while hot onto ice and carefully adjusted to pH=12 using 20% NaOH. The phosphate which precipitates in the process is dissolved by addition of water. The product is subsequently extracted with toluene, converted into the hydrochloride using 1 N HCl and extracted with sufficient water. The aqueous phase is rendered basic again using 20% NaOH with ice-cooling, the reaction product is extracted with toluene, dried over MgSO4 and evaporated to dryness under reduced pressure, giving 89.7 g (432.9 mmol) of a viscous yellow oil, corresponding to 97% of theory.

Provenance & Evidence