Pyridine → 3-Thiophenecarboxamide,N-ethyl-

HRID 610894Notes

Reaction equation

HRID 610894 reaction equation
[S:1]1[CH:5]=[CH:4][C:3]([C:6]([OH:8])=O)=[CH:2]1.S(Cl)(Cl)=O.Cl.[CH2:14]([NH2:16])[CH3:15].N1C=CC=CC=1>CN(C=O)C.C(Cl)Cl>[CH2:14]([NH:16][C:6]([C:3]1[CH:4]=[CH:5][S:1][CH:2]=1)=[O:8])[CH3:15]

Participants

7

Reactant 4

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

Product 1

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

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Procedure

A mixture of thiophene-3-carboxylic acid (20.0 g, 178 mmol), thionyl chloride (30 mL, 411 mmol), and catalytic DMF (5 drops) was stirred at RT overnight. This solution was concentrated under vacuum, and stripped several times from toluene to remove all traces of excess thionyl chloride. Ethyl amine hydrochloride (29.03 g, 356 mmol) was then added to a solution of this crude acid chloride dissolved in CH2Cl2 (50 mL). Pyridine (31.64 g, 400 mmol) was added, and after 1 h of stirring the reaction was washed with 10% HCl followed with water, dried (MgSO4), concentrated, and recrystallized from EtOAc/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. concentrationThis solution was concentrated under vacuum
  2. customto remove all traces of excess thionyl chloride
  3. stirringafter 1 h of stirring the reaction
  4. washwas washed with 10% HCl
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated
  7. customrecrystallized from EtOAc/hexanes

Sources & evidence

ORD record
ord-f85a34e912f245c48802b0384f0e6b7a
Source dataset
uspto-grants-1999_12
Patent number
US05998466

Reaction notes

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