Phosphorus oxychloride → 4-Chloro-6,6-dimethyl-5,6,7,8-tetrahydroquinazoline

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Reaction Steps

To 6,6-dimethyl-5,6,7,8-tetrahydroquinazolin-4(3H)-one (6.41 g, 36 mmol) in chloroform (10 mL) added phosphorus oxychloride (10 mL) and refluxed for 2 hours. The mixture was concentrated to an oil, then diluted with ethyl acetate (80 mL) and washed with saturated sodium carbonate (50 mL) and brine (25 mL). The solution was dried over anhydrous sodium sulfate, filtered and concentrated, then the residue purified by silica gel column chromatography (ethyl acetate/hexanes, 1:8) to give 4-chloro-6,6-dimethyl-5,6,7,8-tetrahydroquinazoline (5.3 g, 75% yield) as a yellow solid. 1H NMR (400 MHz, CDCl3): 8.72 (s, 1H), 2.52 (t, 2H), 2.14 (s, 2H), 1.48 (t 2H), 0.93 (s, 6H); MS (EI) for C10H13ClN2: 197 (MH+).

Provenance & Evidence