A mixture of N-(4-tert-butylphenyl)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-4-amine 0.173 g, 0.61 mmol), 2,3-dichloropyridine (0.91 g, 0.61 mmol) and potassium carbonate (0.234 g, 1.84 mmol) in DMF was heated in a sealed tube in a microwave (Emrys Optimizer model, Personal Chemistry) at 200° C. for 2 h. The mixture was cooled to r.t. and diluted with water (30 mL). The mixture was extracted with ethyl acetate (3×30 mL). The combined organic extracts were washed with brine, dried over sodium sulfate and concentrated to leave an oil. The product was purified by silica gel chromatography (ethyl acetate/hexane gradient) to obtain 0.035 g of the title compound as a light yellow oil. The oil was dissolved in 1 ml ethyl acetate and treated with 1.0 M HCl in diethyl ether (0.09 mL). The resulting solid was collected by filtration, washed with diethyl ether and dried to give 0.030 g light yellow solid.
