Hydrochloric Acid → 7-Ethyl-2-methyl-4-oxo-4,7-dihydrothieno(2,3-b)pyridine-5-carboxylic acid

HRID 1679118Notes

Reaction equation

HRID 1679118 reaction equation
C([O:3][C:4]([C:6]1[C:7]([OH:16])=[C:8]2[CH:14]=[C:13]([CH3:15])[S:12][C:9]2=[N:10][CH:11]=1)=[O:5])C.[OH-].[K+].[CH2:19](I)[CH3:20].Cl>O.C(O)C>[CH2:19]([N:10]1[CH:11]=[C:6]([C:4]([OH:3])=[O:5])[C:7](=[O:16])[C:8]2[CH:14]=[C:13]([CH3:15])[S:12][C:9]1=2)[CH3:20]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6340IodoethaneHCID 14797Potassium HydroxideHCID 178469715HCID 178469715, compound

Product 1

HCID 30452477-Ethyl-2-methyl-4-oxo-4,7-dihydrothieno(2,3-b)pyridine-5-carboxylic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent2×

Procedure

A mixture of 1.4 parts of ethyl-4-hydroxy-2-methylthieno(2,3-b)pyridine-5-carboxylate, 12 parts by volume of 10% aqueous potassium hydroxide, 48 parts by volume of ethanol, 60 parts by volume of water and 1.8 parts by volume of ethyl iodide is refluxed for about 3 hours. After cooling, the reaction mixture is added to 60 parts by volume of water containing 3 parts by volume of concentrated hydrochloric acid and the resulting crystals are collected by filtration to give 7-ethyl-4,7-dihydro-2-methyl-4-oxothieno(2,3-b)pyridine-5-carboxylic acid as colorless crystals. Recrystallization from chloroform-ethanol yields colorless prisms melting at 229°-230° C.

Workup

  1. temperatureis refluxed for about 3 hours
  2. temperatureAfter cooling
  3. filtrationthe resulting crystals are collected by filtration

Sources & evidence

ORD record
ord-935c9c15185b47bf8c96f81e17aca99c
Source dataset
uspto-grants-1978_03
Patent number
US04079060

Reaction notes

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