Ethanimidic acid, ethyl ester, hydrochloride (1:1) → Methyl 5-(5-Methyl-1,3,4-oxadiazol-2-yl)-2-thiophenecarboxylate

HRID 566199Notes

Reaction equation

HRID 566199 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:9][C:8]([C:10]([NH:12][NH2:13])=[O:11])=[CH:7][CH:6]=1)=[O:4].Cl.[C:15](=N)(OCC)[CH3:16]>N1C=CC=CC=1>[CH3:15][C:16]1[O:11][C:10]([C:8]2[S:9][C:5]([C:3]([O:2][CH3:1])=[O:4])=[CH:6][CH:7]=2)=[N:12][N:13]=1

Participants

4

Reactant 2

HCID 2724290Ethanimidic acid, ethyl ester, hydrochloride (1:1)HCID 148719615-Methoxycarbonyl-2-thiophenecarboxylic acid hydrazide

Product 1

HCID 14871962Methyl 5-(5-Methyl-1,3,4-oxadiazol-2-yl)-2-thiophenecarboxylate

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A stirred suspension of 5-methoxycarbonyl-2-thiophenecarboxylic acid hydrazide (548 mg, 2.74 mmoles) and ethyl acetimidate hydrochloride (372 mg, 3.01 mmoles) in 10 ml of pyridine was refluxed for four hours, cooled to room temperature and evaporated in vacuo. The residual oily solid was dissolved in ethyl acetate and washed with water, 1N hydrochloric acid and 5% sodium bicarbonate. The ethyl acetate was dried (magnesium sulfate) and evaporated in vacuo to a pale tan solid (242 mg, 39%), m.p. 142-5° C. This material was used directly without further purification. Exact Mass: 224.0253, Calculated: 224.0256; EIMS (m/z): 224 (M+, base), 193 (M+—CH3O, 33%), 169 (C7H5O3S, 83%); 1HNMR (DMSO-d6) delta, 7.88 (1H, d, J=3.9 Hz), 7.80 (1H, d, J=3.9 Hz), 3.87 (3H, s), 2.58 (3H, s); ir (potassium bromide): 1705, 1571, 1291, 1101, 751 cm−1.

Workup

  1. temperaturewas refluxed for four hours
  2. customevaporated in vacuo
  3. dissolutionThe residual oily solid was dissolved in ethyl acetate
  4. washwashed with water, 1N hydrochloric acid and 5% sodium bicarbonate
  5. dry with materialThe ethyl acetate was dried (magnesium sulfate)
  6. customevaporated in vacuo to a pale tan solid (242 mg, 39%), m.p. 142-5° C
  7. customThis material was used directly without further purification

Sources & evidence

ORD record
ord-3304a6cbe51f46588f0b27b9c4de34bf
Source dataset
uspto-grants-2001_01
Patent number
US06174883B1

Reaction notes

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