Trifluoroacetic acid → 5-(4-Chlorophenyl)-1,3,4-thiadiazol-2-amine

HRID 1262830Notes

Reaction equation

HRID 1262830 reaction equation
FC(F)(F)C(O)=O.[Cl:8][C:9]1[CH:16]=[CH:15][C:12]([C:13]#[N:14])=[CH:11][CH:10]=1.N[NH:18][C:19]([NH2:21])=[S:20].[OH-].[NH4+]>O>[NH2:21][C:19]1[S:20][C:13]([C:12]2[CH:15]=[CH:16][C:9]([Cl:8])=[CH:10][CH:11]=2)=[N:14][N:18]=1

Participants

6

Reactant 4

HCID 6422Trifluoroacetic acidHCID 121634-ChlorobenzonitrileHCID 14923Ammonium HydroxideHCID 2723789Thiosemicarbazide

Product 1

HCID 6683925-(4-Chlorophenyl)-1,3,4-thiadiazol-2-amineYield 35.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To 125 ml of stirred trifluoroacetic acid at room temperature was added 4-chlorobenzonitrile (50.0 g, 0.365 mole), followed by the slow addition of thiosemicarbazide (35.0 g, 0.386 mole). Upon complete addition, the reaction mixture was heated under reflux for 60 hours. The cooled reaction mixture was poured into a mixture of 150 ml of ice and 150 ml of water, then made basic by addition of 150 ml of concentrated ammonium hydroxide. After standing for 16 hours, a crystalline solid was isolated from the mixture by filtration. The solid was recrystallized from 900 ml of ethanol to give 2-amino-5-(4-chlorophenyl)-1,3,4-thiadiazole (27.5 g, mp 227°-229° C.).

Workup

  1. additionUpon complete addition
  2. temperaturethe reaction mixture was heated
  3. temperatureunder reflux for 60 hours
  4. customThe cooled reaction mixture
  5. customa crystalline solid was isolated from the mixture by filtration
  6. customThe solid was recrystallized from 900 ml of ethanol

Sources & evidence

ORD record
ord-c3666a07acdd4f2e8f0b683ab909b217
Source dataset
uspto-grants-1984_06
Patent number
US04454147

Reaction notes

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