2-Thiopheneglyoxylic acid → 2-Hydroxyimino(thien-2-yl)acetic acid

HRID 1729969Notes

Reaction equation

HRID 1729969 reaction equation
[OH:1][NH:2]Cl.C(=O)(O)[O-].[Na+].[S:9]1[CH:13]=[CH:12][CH:11]=[C:10]1[C:14](=O)[C:15]([OH:17])=[O:16]>O>[OH:1][N:2]=[C:14]([C:10]1[S:9][CH:13]=[CH:12][CH:11]=1)[C:15]([OH:17])=[O:16]

Participants

5

Reactant 3

HCID 776942-Thiopheneglyoxylic acidHCID 149953Hydroxylamine, N-chloro-HCID 516892Sodium Bicarbonate2×

Product 1

HCID 736296442-Hydroxyimino(thien-2-yl)acetic acidYield 51%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

A cooled solution of hydroxylamino hydrochloride (0.884 g) and sodium bicarbonate (1.08 g) in water (20 ml.) was added to a cooled (0°) solution of thien-2-yl-glyoxylic acid (2.0 g) and sodium bicarbonate (1.08 g) in water (20 ml.). After two days at 20° the solution was extracted with ether, cooled and acidified with concentrated hydrochloric acid. The resulting white solid was filtered off (0.564 g) and the filtrate was then thoroughly extracted with ether. The combined extracts were washed with brine, dried and concentrated. The solid residue was triturated with benzene to give the oxime (syn-isomer) (1.05 g; 51%), m.p. 1320,λmax. (ethanol) 284 mm (ε9,500), νmax. (Nujol) 2590 and 1706 (CO2H) and 1655 cm-1 (C=N), (DMSO-d6), -2.5 to -9.5 (broad multiplet; N-OH and COOH), 2.36 (multiplet; thienyl C-5 H) and 2.82 (multiplet; thienyl C-3 H and C-4 H).

Workup

  1. extractionAfter two days at 20° the solution was extracted with ether
  2. temperaturecooled
  3. filtrationThe resulting white solid was filtered off (0.564 g)
  4. extractionthe filtrate was then thoroughly extracted with ether
  5. washThe combined extracts were washed with brine
  6. customdried
  7. concentrationconcentrated
  8. customThe solid residue was triturated with benzene

Sources & evidence

ORD record
ord-21d1ee193ee941c89a2135d4a666f620
Source dataset
uspto-grants-1976_11
Patent number
US03991046

Reaction notes

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