反应详情

温度

100 °C

A suspension of 8-Methoxy-5,6-dihydro-benzo[h]quinazolin-2-ol as a 1:1 urea complex from preparation 1 (20 g, 69.0 mM) in POCl3 (350 ml) was heated under nitrogen atmosphere at 100° C. for 20 hr. The POCl3 was removed under reduced pressure and the residue was suspended in dichloromethane (300 ml) and cooled in an ice bath and then concentrated sodium bicarbonate (500 ml) was carefully added followed by 1 N NaOH (200 ml) and the phases separated. The aqueous phase was extracted with dichloromethane (3×500 ml) and the pooled organic phases were dried over Na2SO4, filtered and the filtrate evaporated under reduced pressure to give 2-Chloro-8-methoxy-5,6-dihydro-benzo[h]quinazoline (2, 14.46 g, 86% yield) as a yellow solid. ES-MS MH+ 247.1. 1H NMR (300 MHz, ppm, DMSO-d6): 8.54 (s, 1H), 8.09 (d, 1H), 6.99 (m, 3H) 3.84 (s, 3H), 2.91 (m, 4H).

1. customThe POCl3 was removed under reduced pressure
2. temperaturecooled in an ice bath
3. additionconcentrated sodium bicarbonate (500 ml) was carefully added
4. customthe phases separated
5. extractionThe aqueous phase was extracted with dichloromethane (3×500 ml)
6. dry with materialthe pooled organic phases were dried over Na2SO4
7. filtrationfiltered
8. customthe filtrate evaporated under reduced pressure