Methanol → Ethyl 2-(acetylamino)-4-methylthiophene-3-carboxylate

HRID 2057505Notes

Reaction equation

HRID 2057505 reaction equation
Cl[CH2:2][C:3](=O)[CH3:4].[SH-:6].[Na+].[CH2:8]([O:10][C:11](=[O:15])[CH2:12][C:13]#[N:14])[CH3:9].C(N([CH2:21][CH3:22])CC)C.C[OH:24]>O>[C:21]([NH:14][C:13]1[S:6][CH:2]=[C:3]([CH3:4])[C:12]=1[C:11]([O:10][CH2:8][CH3:9])=[O:15])(=[O:24])[CH3:22]

Participants

7

Reactant 5

HCID 887MethanolHCID 6571ChloroacetoneHCID 7764Ethyl cyanoacetateHCID 8471TriethylamineHCID 28015Sodium hydrosulfide

Product 1

HCID 290215Ethyl 2-(acetylamino)-4-methylthiophene-3-carboxylate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Chloroacetone was reacted with sodium hydrosulphide in aqueous methanol, and the resulting solution containing the reaction product treated with ethylcyanoacetate in the presence of triethylamine at the boil. Addition of water precipitated 2-amino-3-ethoxycarbonyl-4-methylthiophene which was reacted with acetic anhydride to give 2-acetylamino-3-ethoxycarbonyl-4-methylthiophene which on hydrolysis with an aqueous solution of sodium hydroxide was converted to 2-acetylamino-4-methylthiophene-3-carboxylic acid. This was decarboxylated by heating in N:N-diethylaniline at 220° C., and the resulting 2-acetylamino-4-methylthiophene dinitrated in sulphuric acid medium at -5° C. The resulting product was then heated in an aqueous solution of sulphuric acid to remove the N-acetyl group.

Workup

  1. additionthe resulting solution containing the reaction product
  2. customprecipitated 2-amino-3-ethoxycarbonyl-4-methylthiophene which
  3. customwas reacted with acetic anhydride

Sources & evidence

ORD record
ord-377582247091471b849ebe844fe691bc
Source dataset
uspto-grants-1980_07
Patent number
US04211696

Reaction notes

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