39576-83-5

The general procedure for the synthesis of 2,4-dichloro-8-methylquinazoline from 2,4-dihydroxy-8-methylquinazoline was as follows: 8-methylquinazoline-2,4(1H,3H)-dione (4.50 g, 25.50 mmol) was added to phosphorochloridic acid (47.6 mL, 510.9 mmol). The reaction mixture was stirred at 100 °C for 6 h and subsequently cooled to room temperature. The reaction solution was slowly poured into water (300 mL) and the internal temperature was controlled to be below 60°C. After precipitating the solid, the product was collected by filtration to afford 2,4-dichloro-8-methylquinazoline (4.30 g, 79% yield).

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[3] Patent: EP322133, 1991, B1
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