Hydrochloric Acid → 4-Chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid

HRID 917775Notes

Reaction equation

HRID 917775 reaction equation
C([O:3][C:4]([C:6]1[C:11]([Cl:12])=[CH:10][C:9](=[O:13])[N:8]([CH3:14])[CH:7]=1)=[O:5])C.[OH-].[Na+].Cl>O1CCCC1.C(#N)C.O>[Cl:12][C:11]1[C:6]([C:4]([OH:5])=[O:3])=[CH:7][N:8]([CH3:14])[C:9](=[O:13])[CH:10]=1

Participants

7

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 11615451Ethyl 4-chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylate

Product 1

HCID 116655334-Chloro-1-methyl-6-oxo-1,6-dihydropyridine-3-carboxylic acidYield 37.2%

Reagents, catalysts & solvents 3

HCID 962WaterSolvent2×HCID 6342AcetonitrileSolventHCID 8028TetrahydrofuranSolvent

Procedure

4-Chloro-1-methyl-6-oxo-1,6-dihydro-pyridine-3-carboxylic acid ethyl ester (2.65 g, 12.3 mmol) was dissolved in a mixture of tetrahydrofuran (16 mL), acetonitrile (16 mL) and water (8 mL). Sodium hydroxide (1.23 g, 30.8 mmol) was added and the reaction mixture was allowed to stir at ambient temperature for 24 h. The reaction mixture was diluted with water (50 mL) and was acidified to pH 2 with 1 M hydrochloric acid and was extracted many times with ethyl acetate (about 1 L). The extracts were dried over anhydrous magnesium sulfate and concentrated in vacuo to afford an orange-tinged solid. Crystallization from methanol-ethyl acetate afforded 4-chloro-1-methyl-6-oxo-1,6-dihydro-pyridine-3-carboxylic acid (0.859 g, 37% yield) as an off-white solid: 1H NMR (DMSO-d6, 400 MHz) δ 13.02 (br s, 1H), 8.58 (s, 1H), 6.58 (s, 1H), 3.48 (s, 3H).

Workup

  1. extractionwas extracted many times with ethyl acetate (about 1 L)
  2. dry with materialThe extracts were dried over anhydrous magnesium sulfate
  3. concentrationconcentrated in vacuo
  4. customto afford an orange-tinged solid
  5. customCrystallization from methanol-ethyl acetate

Sources & evidence

ORD record
ord-f8d87639dc8e40cea4d24ea9eb0e80b4
Source dataset
uspto-grants-2007_09
Patent number
US07273877B2

Reaction notes

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