反应详情

To a solution of 9.0 g of 9-methoxy-4-propyl-1,2,3,5-tetrahydro-4H-[1]-benzopyrano[3,4-b]pyridin-1-one in 90 ml of dry pyridine at 0° is added 0.90 g of lithium aluminium hydride. After 20 minutes at 30° the reaction is quenched with 1.8 ml of 10% sodium hydroxide, the reaction mixture is diluted with ethyl acetate, dried over magnesium sulfate and filtered. The filter cake is washed well with 10% methanol/methylene chloride and the solvent is removed in vacuo from the combined filtrates. The entire above reduction procedure is repeated on the residue using tetrahydrofuran instead of pyridine as the initial reaction solvent. The product is triturated with ether to afford a white powder which is treated with 28 ml of pyridine and 6.3 ml of phosphorus oxychloride at 65° for 30 minutes. The reaction mixture is poured onto a mixture of ice and sodium carbonate solution, and the product is extracted with ethyl acetate. After drying over magnesium sulfate, the solvent is removed in vacuo to afford, as an oil, 9-methoxy-4-propyl-2,3,4a,5-tetrahydro-4H-[1]-benzopyrano[3,4-b]pyridine; NMR: δ 0.90 (3H,t), 3.75 (3H,s).

1. customAfter 20 minutes at 30° the reaction is quenched with 1.8 ml of 10% sodium hydroxide
2. additionthe reaction mixture is diluted with ethyl acetate
3. dry with materialdried over magnesium sulfate
4. filtrationfiltered
5. washThe filter cake is washed well with 10% methanol/methylene chloride
6. customthe solvent is removed in vacuo from the combined filtrates
7. customreaction solvent
8. customThe product is triturated with ether
9. customto afford a white powder which
10. extractionthe product is extracted with ethyl acetate
11. dry with materialAfter drying over magnesium sulfate
12. customthe solvent is removed in vacuo