Tetrahydrofuran → Chroman

Temperature

20 °C

To a suspension of lithium aluminium hydride (120 mg, 3 mmol) in dry tetrahydrofuran (20 ml) at 0° C. under nitrogen was added dropwise a solution of 3,4-dihydro-1-benzopyran-2-(4'-phenylpiperidinyl)carboxamide (480 mg, 1.5 mmol) in dry tetrahydrofuran (20 ml). The mixture was stirred at 0° C. for 1/2 hour and at 20° C. for 3 hours. Wet ethyl acetate (10 ml) was added dropwise then saturated sodium potassium tartrate (20 ml). After stirring for 1 hour, the mixture was extracted with ethyl acetate (4×50 ml). The combined organic extracts were washed with water and brine, dried over anhydrous magnesium sulphate and concentrated in vacuo to give a pale yellow oil. Chromatography on silica gave the title compound 2-[4'-phenylpiperidinyl)methyl]-3,4-dihydro-1-benzopyran (0.37 g, 80%) as a colourless oil having the following characteristics:

1. stirringAfter stirring for 1 hour
2. extractionthe mixture was extracted with ethyl acetate (4×50 ml)
3. washThe combined organic extracts were washed with water and brine
4. dry with materialdried over anhydrous magnesium sulphate
5. concentrationconcentrated in vacuo
6. customto give a pale yellow oil

ORD record

ord-6915322aab8e44ac9635771eec8872e4

Source dataset

uspto-grants-1988_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04745114