反应详情

A mixture of 6.4 g of 5-methoxy-3,4-dihydro-2H-[1]-benzopyran-3-one, 30 ml of dipropylamine, 0.5 ml of trifluoroacetic acid and 200 ml of toluene is refluxed in a Dean-Stark apparatus for 3 hours. The solution concentrated in vacuo and the residue is added to a solution of 7 g of sodium cyanoborohydride in 160 ml of ethanol and 40 ml of acetic acid. After 15 minutes at room temperature most of the solvent is removed in vacuo. The residue is dissolved in 6N hydrochloric acid and washed with ether. The aqueous layer is made basic and the product is extracted with ether. The aqueous layer is made basic and the product is extracted with ether. The ether layer is dried over magnesium sulfate and the solvent is removed in vacuo, to afford 5-methoxy-3,4-dihydro-N,N-dipropyl-2H-[1]-benzopyran-3-amine which is treated with ethanolic hydrochloric acid to afford 5-methoxy-3,4-di-hydro-N,N-dipropyl-2H-[1]-benzopyran-3-amine hydrochloride, m.p. 219°-221°.

1. temperatureis refluxed in a Dean-Stark apparatus for 3 hours
2. concentrationThe solution concentrated in vacuo
3. additionthe residue is added to a solution of 7 g of sodium cyanoborohydride in 160 ml of ethanol and 40 ml of acetic acid
4. customAfter 15 minutes at room temperature most of the solvent is removed in vacuo
5. dissolutionThe residue is dissolved in 6N hydrochloric acid
6. washwashed with ether
7. extractionthe product is extracted with ether
8. extractionthe product is extracted with ether
9. dry with materialThe ether layer is dried over magnesium sulfate
10. customthe solvent is removed in vacuo