Pentifylline

PreparationNaH (444 mg, 11 mmol, 60% in mineral oil) was washed with hexane (2 × 8 mL) and then suspended in DMSO (30 mL) under nitrogen. The NaH solution was heated to 60 °C with stirring, and then theobromine (1.2 g, 11 mmol) was added as a solid in one go. After 20 minutes, the desired alkyl halide (11 mmol) was added in one go, allowing the reaction to proceed overnight, then cooled to room temperature and quenched with water (2 mL). After concentrating the solution under vacuum, the resulting solid was resuspended in CHCl3 (50 mL). The solution was washed with saturated ammonium chloride (20 mL), then washed with brine (20 mL) and concentrated. 1-N-HEXYLTHEOBROMINE (5): Yield of recovery = 2.6 g pale yellow solid, 89%.