Hydrochloric Acid → 5-(5-Chloro-2-thienyl)-4-(2-methoxyethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one

HRID 220683Notes

Reaction equation

HRID 220683 reaction equation
[Cl:1][C:2]1[S:6][C:5]([C:7]([NH:9][NH:10][C:11]([NH:13][CH2:14][CH2:15][O:16][CH3:17])=[O:12])=O)=[CH:4][CH:3]=1.[OH-].[Na+].Cl>>[Cl:1][C:2]1[S:6][C:5]([C:7]2[N:13]([CH2:14][CH2:15][O:16][CH3:17])[C:11](=[O:12])[NH:10][N:9]=2)=[CH:4][CH:3]=1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium Hydroxide2×HCID 595369432-[(5-Chloro-2-thienyl)carbonyl]-N-(2-methoxyethyl)hydrazinecarboxamide

Product 1

HCID 595368995-(5-Chloro-2-thienyl)-4-(2-methoxyethyl)-2,4-dihydro-3H-1,2,4-triazol-3-one

Procedure

Of the compound from Example 167A, 4.85 g (17.46 mmol) were dissolved in 17 ml (52.39 mmol) of 3M aqueous sodium hydroxide solution and heated under reflux for 168 h. During this, after 16, 40, 64 and 88 h, 1.05 g portions (26.19 mmol, in total 104.76 mmol) of solid sodium hydroxide were added. The batch was acidified to pH 10 using 1M hydrochloric acid, and the mixture was extracted with twice 30 ml of ethyl acetate. The combined organic phases were dried over sodium sulphate, filtered, freed from the solvent on a rotary evaporator and dried in an HV. This gave 2.44 g (54% of theory) of the title compound.

Workup

  1. temperatureheated
  2. temperatureunder reflux for 168 h
  3. extractionthe mixture was extracted with twice 30 ml of ethyl acetate
  4. dry with materialThe combined organic phases were dried over sodium sulphate
  5. filtrationfiltered
  6. customfreed from the solvent on a rotary evaporator
  7. customdried in an HV

Sources & evidence

ORD record
ord-b2fa4fb20d12412491d22b79a3b1781c
Source dataset
uspto-grants-2012_06
Patent number
US08202895B2

Reaction notes

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