3-Pyridinecarboxaldehyde → HCID 11993991, compound

Participants

Reaction Steps

(See FIG. 11.) To a solution of nicotinaldehyde (150 μL, 1.59 mmol) in 95% EtOH (5 mL) was added 2-tosylhydrazine (296 mg, 1.59 mmol) and the resultant solution was stirred at room temperature for 2 h. To the solution was added aqueous sodium hydroxide (5 N, 0.32 mL, 1.59 mmol) and the solution was stirred for 20 min. To the solution was added a solution of tert-butyl prop-2-ynylcarbamate (1.23 g, 7.95 mmol) and the resultant solution was warmed to 50° C. and stirred under an argon atmosphere for 96 h. The solution was poured into a water/EtOAc mixture (1:1, 100 mL), the organic fraction was collected and the aqueous fraction was extracted with EtOAc (2×20 mL). The combined organic fractions were dried (Na2SO4), filtered and the solvent was removed in vacuo. The crude material was chromatographed on silica gel (EtOAc/Hex, 50/50, Rf=0.08) to afford the title compound 31 (158 mg, 36% yield) as a white solid: mp=185-187° C.; 1H NMR. (CDCl3) δ 8.92 (m, 1H), 8.50 (m, 1H), 8.01 (m, 1H), 7.28 (m, 1H), 6.47 (s, 1H); 5.62 (br s, 1H); 4.34 (d, J=6 Hz, 1H), 1.45 (s, 9H); LRMS (ESI) m/z calcd for C14H19N4O2 [M+H]+ 275. found 275.

Provenance & Evidence