Pyridine → 3-Thiophenecarboxamide,N-ethyl-

HRID 610929Notes

Reaction equation

HRID 610929 reaction equation
[S:1]1[CH:5]=[CH:4][C:3]([C:6]([OH:8])=O)=[CH:2]1.S(Cl)(Cl)=O.[N:13]1C=CC=[CH:15][CH:14]=1.Cl.C(N)C>CN(C=O)C.C1(C)C=CC=CC=1.C(Cl)Cl>[CH2:14]([NH:13][C:6]([C:3]1[CH:4]=[CH:5][S:1][CH:2]=1)=[O:8])[CH3:15]

Participants

8

Reactant 4

HCID 1049PyridineHCID 6918Thiophene-3-carboxylic acidHCID 11198Ethylamine hydrochlorideHCID 24386Thionyl Chloride

Product 1

HCID 154523283-Thiophenecarboxamide,N-ethyl-Yield 76%

Reagents, catalysts & solvents 3

HCID 6228DimethylformamideCatalystHCID 1140TolueneSolventHCID 6344DichloromethaneSolvent

Procedure

A mixture of 3-thiophenecarboxylic acid (20 g, 178 mmol), thionyl chloride (30 mL), and DMF (5 drops) was stirred overnight, then was concentrated under vacuum and stripped several times from toluene to remove all traces of excess thionyl chloride. Pyridine (31.64 g, 400 mmol) was added dropwise to a mixture of this acid chloride and ethylamine hydrochloride in toluene (5 mL) and CH2Cl2 (50 mL). After stirring for 1 h, the reaction was washed with 10% aq HCl followed with water, then was dried (MgSO4), concentrated, and crystallized from ethyl acetate/hexanes to give 14.9 g of N-ethyl-3-thiophenecarboxamide as a tan solid, a 76% yield. m.p. 115°-117° C.

Workup

  1. concentrationwas concentrated under vacuum
  2. customto remove all traces of excess thionyl chloride
  3. stirringAfter stirring for 1 h
  4. washthe reaction was washed with 10% aq HCl
  5. dry with materialwas dried (MgSO4)
  6. concentrationconcentrated
  7. customcrystallized from ethyl acetate/hexanes

Sources & evidence

ORD record
ord-c67427f00c0547d1a3280d561fc6c95d
Source dataset
uspto-grants-1999_12
Patent number
US05998466

Reaction notes

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