Pyridine → HCID 57606115, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 5-(Piperidine-1-carbonyl)-thiophene-2-carbaldehyde (Preparative Example 17, 2.23 g, 10 mmol) in EtOH (50 mL) was treated with pyridine (971 μL, 12 mmol, 1.2 eq) followed by hydroxylamine hydrochloride (833 mg, 12 mmol, 1.2 eq) and heated at reflux for 2 hr then evaporated in vacuo. The crude intermediate oxime was then dissolved in acetic anhydride and heated at 145° C. for 16 hr then evaporated in vacuo to a small volume which was partitioned between EtOAc (50 mL) and water (200 mL). The organic layer was further washed with a brine solution (50 mL), dried over MgSO4, filtered, evaporated in vacuo and the residue chromatographed on silica gel with EtOAc/hexanes (30 then 50%) as eluant to afford product as a yellow-tinted oil (1.43 g, 65%). 1H NMR (CDCl3) 1.65-1.76 (m, 6 H), 3.64 (br s, 4 H), 7.23 (d, J=4.0, 1 H), 7.56 (d, J=4.0, 1 H). 13C NMR 24.5, 26.2, 44.3 (br), 48.5 (br), 111.9, 113.7, 128.0, 137.0, 144.7, 161.3. LC/MS 5.09 min, [M+1]+ 221.

Provenance & Evidence