Trifluoroacetic acid → HCID 53847737, compound

Participants

Reaction Steps

Trifluoroacetic acid (5 ml) was added to a solution of 2-amino-N-[(1-tert-butoxycarbonyl-4-piperidyl)methyl]pyridine-3-carboxamide (0.92 g; prepared in a similar manner to that described in Example 2) in dichloromethane (10 ml) then the mixture stirred at ambient temperature for 2 hours and the solvent removed in vacuo. The crude 2-amino-N-(4-piperidylmethyl)pyridine-3-carboxamide trifluoroacetate thus produced was dissolved in anhydrous acetonitrile (10 ml) and potassium carbonate (1.5 g) was added, followed by a solution of (R)-7-methyl-1,4-benzodioxan-2-ylmethyl 4-toluenesulphonate (0.9 g) in anhydrous acetonitrile (5 ml). The mixture was heated under reflux for 18 hours then poured onto water and extracted with ether (2×100 ml). The combined extracts were washed with water then extracted with hydrochloric acid (1M; 50 ml). The acid extracts were washed with ether (100 ml) then basified with sodium hydrogen carbonate and extracted with ether (2×100 ml). These extracts were combined, washed with water and dried over magnesium sulphate. The solvent was evaporated and the residue purified by flash chromatography on silica eluting with a 20:1 mixture of dichloromethane and methanol. Appropriate fractions were combined and evaporated to give (S)-2-amino-N-{[1-(7-methyl-1,4-benzodioxan-2-ylmethyl)-4-piperidyl]methyl}pyridine-3-carboxamide as a colourless solid (0.36 g) m.p. 143-146° C., [α]D -46.23° (c=0.53, methanol).

Provenance & Evidence