[NH2:1][NH:2][C:3]([NH2:5])=[S:4].[Br:6][C:7]1[CH:8]=[C:9]([CH:12]=[CH:13][CH:14]=1)[CH:10]=O>O.C(O)C.O.O.O.O.O.O.[Fe](Cl)(Cl)Cl>[Br:6][C:7]1[CH:8]=[C:9]([C:10]2[S:4][C:3]([NH2:5])=[N:2][N:1]=2)[CH:12]=[CH:13][CH:14]=1To a solution of thiosemicarbazide (0.493 g, 5.40 mmol, 1.0 equiv) in 6 mL of water at 70° C. is added a solution of 3-bromobenzaldehyde (0.633 ml, 5.40 mmol, 1.0 equiv) in 4.5 mL ethanol. After the precipitate formed, iron(III) chloride hexahydrate (2.92 g, 10.81 mmol, 2.0 equiv) in 6 mL water is added and the mixture is stirred for 2.5 h at 85° C. Upon completion, the mixture is allowed to cool to room temperature and the resulting precipitate is collected by filtration and taken up in 12 mL pyridine. Ice water is then added to the pyridine slurry. The mixture is cooled then filtered to give 5-(3-bromophenyl)-1,3,4-thiadiazol-2-amine (553 mg, 39.9% yield) as a brown solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.85-7.88 (m, 1H), 7.67 (d, J=8.22 Hz, 1H), 7.53-7.59 (m, 1H), 7.45 (s, 2H), 7.36 (t, J=8.02 Hz, 1H);
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