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

HRID 703124Notes

Reaction equation

HRID 703124 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, 3.3×10-1 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-2479ca08599448b6b9446b4f4f1acd81
Source dataset
uspto-grants-1991_01
Patent number
US04981863

Reaction notes

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