Dimethylformamide → (2S,4S)-N-[2-(4-Benzylpiperidin-1-yl)ethyl]-6-fluoro-2'5'-dioxospiro[chroman-4,4'-imidazolidine]-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

A mixture of N-(2-aminoethyl)-4-benzylpiperidine (13.0 g, 59.6 mmol), 1,8-diazabicyclo[5,4,0]-7-undecene (10.9 g, 71.7 mmol) and N,N-dimethylformamide (90.0 ml, 1.16 mol) was chilled to -30° C. To the mixture was added over 30 minutes a solution of (2S, 4S)-6-fluoro-2',5'-dioxospiro[chroman-4,4'-imidazolidine]-2-carbonyl chloride (Reference Example, 18.0 g, 60.3 mmol) in N,N-dimethylformamide (90.0 ml, 1.16 mol) and the mixture was stirred for 15 hours at temperature of 15°-25° C. After distilling off the solvent, the reaction mixture was chromatographed on silica gel, eluted with CH2Cl2 /MeOH (9/1) and evaporated in vacuo to dryness to give the desired compound (14.3 g, 50.0%) as colorless amorphous substance.

Provenance & Evidence