N-benzyl-2-pyrrolidone (1.58 ml, 9.85 mmoles) was combined with 2 ml toluene under N2 and cooled to 0°-5°. POCl3 (0.5 ml, 5.9 mmoles) was added and the mixture stirred 30 minutes. Toluene (3 ml) and 1-(3-chloro- phenyl-2(1H,3H)-indolone (1.2 g, 4.92 mmoles) were added and the stirred reaction mixture warmed to 25° for 30 minutes and then to 70°-75° for 18 hours. The reaction mixture was cooled, diluted with 100 ml CH2Cl2, washed with saturated NaHCO3, H2O and brine, dried and concentrated in vacuo to an oil (2.6 g). The oil was chromatographed on silica gel (45×150 mm) using CH2Cl2 as eluant, yielding title product, initially an oil which was crystallized from ether/pentane, 1.04 g (53%), m.p. 72°-75°.
