Chroman-4-one oxime → 3,4-Dihydro-2H-1-benzopyran-4-amine

To a solution of (4E)-2,3-dihydro-4H-chromen-4-one oxime (3.20 g) in tetrahydrofuran (50 ml) under N2 atmosphere was added lithium aluminum hydride (1M THF, 50 ml). The reaction mixture stirred at ambient temperature for 16 h and was quenched with 10 ml of water, 10 ml of 2 N NaOH and 20 ml of water. The reaction mixture was filtered through celite, acidified with 1 N HCl (50 ml), washed with ethyl ether (2×50 ml), basified with 2 N NaOH, extracted methylene chloride (3×100 ml), dried MgSO4, filtered and concentrated. MPLC was run on a biotage 40S column with 2-4% methanol/methylene chloride with 0.5% ammonium hydroxide to provide the title compound as an oil (728 mg, 25%): 1H NMR (300 MHz, CDCl3) δ) 7.34, 7.17, 6.92, 6.85, 4.31-4.24, 4.09, 2.18, 1.91-1.86; HRMS (FAB) calcd for C9H11NO+H 150.0919, found 150.0910.

1. customwas quenched with 10 ml of water, 10 ml of 2 N NaOH and 20 ml of water
2. filtrationThe reaction mixture was filtered through celite
3. washwashed with ethyl ether (2×50 ml)
4. extractionextracted methylene chloride (3×100 ml), dried MgSO4
5. filtrationfiltered
6. concentrationconcentrated

ORD record

ord-ccf8a09a60ad41c1b03c31ef2b9338eb

Source dataset

uspto-grants-2006_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06992087B2