Phosphorus oxychloride → 1-(4-chloro-6,6-dimethyl-5,6,7,8-tetrahydroquinazolin-2-yl)-N,N-dimethylmethanamine

To a solution of the final residue from step 2 in CHCl3 (10 mL) was added POCl3 (10 mL). The reaction mixture was heated (90° C.) for two hours and concentrated. This residue was partitioned between dichloromethane and aqueous sodium bicarbonate and the resulting organic layer was washed with brine, dried over magnesium sulfate, filtered and concentrated in vacuo. Purification by silica gel chromatography (5-10% concentrated aqueous ammonia in methanol) in chloroform provided 1-(4-chloro-6,6-dimethyl-5,6,7,8-tetrahydroquinazolin-2-yl)-N,N-dimethylmethanamine (1.3 g, 48% yield). 1H NMR (400 MHz, CD3OD) δ 4.52 (s, 2H), 3.02 (s, 6H), 2.98 (t, 2H), 2.61 (s, 2H), 1.71 (t, 2H), 1.06 (s, 6H); MS (ES) for C13H20ClN3: 254 (MH+)