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

To a slurry of LAH (38.1 mg, 1.00 mmol) in anhydrous THF (8 ml) was drop wise added (3-thiophen-2-yl-5-thioxo-1,5-dihydro-[1,2,4]triazol-4-yl)-acetic acid (101 mg, 0.42 mmol) in anhydrous THF (4 ml). The mixture was reacted for 2 h and then quenched with saturated aq. Na2SO4 (10 ml). THF was removed under reduced pressure and the residue was made acidic with aq. HCl (3N) and partitioned between EtOAc and water. The aqueous layer was extracted with EtOAc (3×20 ml). The combined organic layers were washed with brine (15 ml), dried (MgSO4) and concentrated under reduced pressure. The crude product was used without purification in the next step. 1H NMR (DMSO-d6), δ (ppm): 13.94 (s, 1H), 7.86 (d, 1H); 7.81 (d, 1H), 7.24 (dd, 1H), 5.09 (t, 1H), 4.16 (t, 2H), 3.76 (app. q, 2H).

Provenance & Evidence