3-Bromobenzaldehyde → 5-(3-Bromophenyl)-1,3,4-thiadiazol-2-amine

HRID 2176432Notes

Reaction equation

HRID 2176432 reaction equation
[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]=1

Participants

6

Reactant 2

HCID 765833-BromobenzaldehydeHCID 2723789Thiosemicarbazide

Product 1

HCID 9211655-(3-Bromophenyl)-1,3,4-thiadiazol-2-amineYield 40%

Reagents, catalysts & solvents 3

HCID 16211236Trichloroiron;hexahydrateCatalystHCID 702EthanolSolventHCID 962WaterSolvent2×

Conditions

Temperature
85 °C

Procedure

To 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 is 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);

Workup

  1. customAfter the precipitate is formed
  2. temperatureto cool to room temperature
  3. filtrationthe resulting precipitate is collected by filtration
  4. additionIce water is then added to the pyridine slurry
  5. temperatureThe mixture is cooled
  6. filtrationthen filtered

Sources & evidence

ORD record
ord-d4c0740e47d84826950a65f58fadf8f6
Source dataset
uspto-grants-2015_06
Patent number
US09066948B2

Reaction notes

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