反应详情

温度

0 °C

5,7-Dimethoxy-3-(4-methoxyphenyl)-4(3H)-quinazolinethione (6.5 g, 19.8 mmol), as prepared in Example 33, was dissolved in 75 ml of CH2Cl2. The solution was cooled to 0° C. and 37 ml of BBr3 (396 mmol) was added dropwise for 1 h 30 min. The reaction mixture was then stirred at room temperature until complete transformation of the starting material as monitored by HPLC. The reaction mixture was evaporated to dryness. A cold saturated solution of NaHCO3 was added and the resulting solid filtered and dried. This solid was mixed with pyridine hydrochloride salt (46 g, 396 mmol). The mixture was heated to 189° C. for 3.5 hours. Subsequently, the reaction was cooled to room temperature. Methanol was added to dissolve the mixture. The obtained dark solution was poured to a saturated NaHCO3 solution and extracted with ethyl acetate. The combined organic phases were washed with brine and dried over MgSO4 to yield a brownish solid that was purified by chromatography on silica gel (loaded with CH2Cl2 and a slight amount of MeOH, eluted with 2%, 2.5%, 3% of MeOH in CH2Cl2) to provide 5,7-dihydroxy-3-(4-hydroxyphenyl)-4(3H)-quinazolinethione (3.4 g, 60%) as a yellow solid.

1. customThe reaction mixture was evaporated to dryness
2. additionA cold saturated solution of NaHCO3 was added
3. filtrationthe resulting solid filtered
4. customdried
5. temperatureThe mixture was heated to 189° C. for 3.5 hours
6. temperatureSubsequently, the reaction was cooled to room temperature
7. dissolutionto dissolve the mixture
8. extractionextracted with ethyl acetate
9. washThe combined organic phases were washed with brine
10. dry with materialdried over MgSO4
11. customto yield a brownish solid
12. customthat was purified by chromatography on silica gel (
13. washa slight amount of MeOH, eluted with 2%, 2.5%, 3% of MeOH in CH2Cl2)