2-[3-sulfanyl-5-(thiophen-2-yl)-4H-1,2,4-triazol-4-yl]acetic acid → 4-(2-Hydroxy-ethyl)-5-thiophen-2-yl-2,4-dihydro-[1,2,4]triazole-3-thione

Participants

Reaction Steps

All of the crude [3-(2-thienyl)-5-thioxo-1,5-dihydro-4H-1,2,4-triazol-4-yl]acetic acid from the previous step was dissolved in THF (20 ml). This solution was added dropwise at 0° C. to a slurry of LAH (2 g) in THF (80 ml) while stirring before allowed to come to r.t. for 2 h. The r.m. was then quenched with sat. Na2SO4 (aq.) at 0° C. and the pH adjusted to 3-4 before filtration through celite. The THF was removed from the filtrate by concentration and the product extracted with EA from the remaining aq. mixture. The EA-phase was then washed with brine and dried over MgSO4 before concentration to dryness to yield a crude material that was recrystallized from MeOH to provide 485 mg of the title compound. 1H NMR (DMSO-d6): 13.94 (br.s, 1H), 7.86 (d, 1H), 7.81 (d, 1H), 7.24 (dd, 1H), 5.09 (t, 1H), 4.16 (t, 2H), 3.76 (q, 2H)

Provenance & Evidence