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

HRID 1973418Notes

Reaction equation

HRID 1973418 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 percent 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-8f5cfeee60fa49c1be3e988a003b2d5e
Source dataset
uspto-grants-1976_12
Patent number
US03997545

Reaction notes

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