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

HRID 1605969Notes

Reaction equation

HRID 1605969 reaction equation
[OH:1][C:2]1[C:7]([C:8]([O:10]CC)=[O:9])=[CH:6][N:5]=[C:4]2[S:13][C:14]([CH3:16])=[CH:15][C:3]=12.[OH-].[K+].[CH2:19](I)[CH3:20].Cl>O.C(O)C>[CH2:19]([N:5]1[CH:6]=[C:7]([C:8]([OH:10])=[O:9])[C:2](=[O:1])[C:3]2[CH:15]=[C:14]([CH3:16])[S:13][C:4]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-81774da60f844bebb678a84126f73edf
Source dataset
uspto-grants-1976_04
Patent number
US03951989

Reaction notes

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