Hydrochloric Acid → 4-Methyl-5-(thiophen-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione

HRID 1199375Notes

Reaction equation

HRID 1199375 reaction equation
[C:1]1([C:6]([NH:8][NH:9][C:10]([NH:12][CH3:13])=[S:11])=O)[S:5][CH:4]=[CH:3][CH:2]=1.C([O-])(O)=O.[Na+].Cl>>[CH3:13][N:12]1[C:6]([C:1]2[S:5][CH:4]=[CH:3][CH:2]=2)=[N:8][NH:9][C:10]1=[S:11]

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 516892Sodium BicarbonateHCID 28198722-Thiophenecarboxylic acid, 2-[(methylamino)thioxomethyl]hydrazide

Product 1

HCID 7219264-Methyl-5-(thiophen-2-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione

Procedure

1-(2-Thenoyl)-4-methylthiosemicarbazide (7.1 g, 3.3×10-2 mole) and 1 molar aqueous NaHCO3 (330 ml, 3.30×10-1 mole) were stirred and heated to reflux. After refluxing about 14 hours the reaction was filtered while hot and the filtrate was then cooled in an ice bath. Acidification by the dropwise addition of concentrated HCl (28 ml, 3.4×10-1 mole) gave a colorless precipitate which was collected by filtration, washed with a little cold H2O, and dried by suction. Crystallization from isopropanol gave colorless spears: 5.0 g (77%), mp 155°-157° C.

Workup

  1. temperatureheated to reflux
  2. temperatureAfter refluxing about 14 hours the reaction
  3. filtrationwas filtered while hot and the filtrate
  4. temperaturewas then cooled in an ice bath
  5. customgave a colorless precipitate which
  6. filtrationwas collected by filtration
  7. washwashed with a little cold H2O
  8. customdried by suction
  9. customCrystallization from isopropanol
  10. customgave colorless spears

Sources & evidence

ORD record
ord-8fa3e45847ce4144b2a18e9029ba54ed
Source dataset
uspto-grants-1990_02
Patent number
US04900743

Reaction notes

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