Trifluoroacetic acid → 1-(6-Aminocarbonylaminoindan-1-ylmethyl)-4-(4-fluorophenyl)piperidine

Participants

Reaction Conditions

Reaction Steps

A solution of potassium isocyanate (1.5 g) dissolved in dichloromethane (20 ml) was cooled to 5° C. and a solution of trifluoroacetic acid (1.9 g) in dichloromethane (20 ml) was added dropwise. To the resulting mixture was added dropwise a solution of 1-(6-aminoindan-1-ylmethyl)-4-(4-fluorophenyl)piperidine, 2a (3 g) in dichloromethane (10 ml). The temperature was allowed to raise to room temperature. After stirring for another 3 hours the mixture was poured on ice (500 g) and diluted aqueous NH4OH was added until pH>9. The organic phase was separated and worked-up as above. The crude title product was purified by column chromatography on silica gel (eluted with 4% triethylamine in ethanol/ethyl acetate 1:3). The purified product (2 g) was dissolved in acetone (20 ml) and added to a solution of fumaric acid (0.6 g) in ethanol (20 ml). The precipitated hemifumarate salt was filtered off and dried. Yield: 1.6 g, mp: 172-174° C. 1H NMR (DMSO-d6): δ 1.65-1.90 (m, 5 H); 2.10-2.35 (m, 3 H); 2.45-2.90 (m, 5 H); 3.10-3.25 (m,2 H); 3.45 (qui, 1 H); 6.85 (s, 2 H); 6.60 (s, 1 H); 7.00-7.15 (m, 4 H); 7.30 (dd, 2 H); 7.45 (s, 1 H); 8.45 (s, 1 H).

Provenance & Evidence