反应详情

6-[N-(2-Benzyloxy-5-bromobenzyl)-N-ethylamino]pyridazine-3-carboxamide (3.24 g, 7.3 mmol) in dichloromethane (50 ml) was treated with boron trichloride dimethyl sulphide reagent (18.5 ml, 2M solution) in dichloromethane (37 mmol) and the solution stirred at ambient temperature for 6 days. The mixture was carefully treated with excess aqueous sodium bicarbonate solution to give a pH of around 9. Dichloromethane was added, the organic and aqueous layers separated and the aqueous layer washed with dichloromethane. The combined organic extracts were then washed with brine, dried and evaporated to give a sticky solid. This was treated with diethylether (30 ml) and methanol (3 ml) and left at ambient temperature overnight. The resultant solid was filtered, washed with diethylether and sucked dry to give 6-[N-(5-bromo-2-hydroxybenzyl)-N-ethylamino]-pyridazine-3-carboxamide (1.34 g, 52%).

1. customto give a pH of around 9
2. customthe organic and aqueous layers separated
3. washthe aqueous layer washed with dichloromethane
4. washThe combined organic extracts were then washed with brine
5. customdried
6. customevaporated
7. customto give a sticky solid
8. waitleft at ambient temperature overnight
9. filtrationThe resultant solid was filtered
10. washwashed with diethylether
11. customsucked dry