Hydrochloric Acid → HCID 21459871, compound

Participants

Reaction Conditions

Reaction Steps

To a 5L flask containing ammonium acetate (450g) which had been thoroughly purged with nitrogen was added a freshly prepared solution of titanium trichloride (300 g, 1.95 mol) in deoxygenated water (2.1L) with ice-bath cooling. To the resulting green solution was added a solution of trans-3-nitro-6-oxo-2-phenylpiperidine (Example 1a, 90 g, 0.409 mol) and sodium methoxide (27 g, 0.5 mol) in methanol (750 ml). The solution was stirred for 1 hr at 0° C. and for a further 1 hr at room temperature. Concentrated hydrochloric acid (240 ml) was added dropwise, and the resulting mixture extracted with ethyl acetate (1000 ml, 3×500 ml). The combined organic extracts were washed with saturated brine (1000 ml), dried (MgSO4), and evaporated under reduced pressure. The residue was suspended in ether and filtered and the pale yellow crystalline solid was washed with ether (3×100 ml) and dried in vacuo to afford 2,5-dioxo-6-phenylpiperidine (58 g, 75%): m.p. 160°-164° C.

Provenance & Evidence