Potassium Hydroxide → HCID 23050230, compound

HRID 1651637Notes

Reaction equation

HRID 1651637 reaction equation
Cl.[NH2:2][OH:3].[OH-].[K+].C([O:8][C:9]([C:11]1[S:15][C:14]2[CH:16]=[C:17]([O:22][CH3:23])[C:18]([O:20][CH3:21])=[CH:19][C:13]=2[CH:12]=1)=O)C>C(O)C>[OH:3][NH:2][C:9]([C:11]1[S:15][C:14]2[CH:16]=[C:17]([O:22][CH3:23])[C:18]([O:20][CH3:21])=[CH:19][C:13]=2[CH:12]=1)=[O:8]

Participants

5

Reactant 3

HCID 14797Potassium HydroxideHCID 443297Hydroxyamine hydrochlorideHCID 45104330Ethyl 5,6-dimethoxybenzo[b]thiophene-2-carboxylate

Product 1

HCID 23050230HCID 23050230, compoundYield 87.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent3×

Procedure

Hydroxylamine hydrochloride (5.3 g) was dissolved in warm ethanol (100 ml). The solution was stirred under an atmosphere of nitrogen and treated with a warm solution of potassium hydroxide (6.4 g) in ethanol (50 ml). After 10 min. a solution of 5,6-dimethoxy-benzo[b]thiophene-2-carboxylic acid ethyl ester (10 g) in ethanol (250 ml) was added and the resultant mixture was allowed to stand at room temperature for 72 hours. The resultant suspension was filtered to remove the precipitated potassium chloride and the filtrate was evaporated to dryness. The resultant yellow residue was dissolved in water (250 ml), filtered and the filtrate was acidified with 5M hydrochloric acid. The precipitated product was filtered and dried at 65° C. under vacuum to give N-hydroxy-5,6-dimethoxy-benzo[b]thiophene-2-carboxamide (8.3 g). A portion crystallised from acetone had a melting point: 179°-180° C.

Workup

  1. filtrationThe resultant suspension was filtered
  2. customto remove the precipitated potassium chloride
  3. customthe filtrate was evaporated to dryness
  4. dissolutionThe resultant yellow residue was dissolved in water (250 ml)
  5. filtrationfiltered
  6. filtrationThe precipitated product was filtered
  7. customdried at 65° C. under vacuum

Sources & evidence

ORD record
ord-f14b2e03d17c4c12900d781a9cca5b67
Source dataset
uspto-grants-1990_05
Patent number
US04929636

Reaction notes

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