Diethyl (ethoxymethylene)malonate → Ethyl 4-Hydroxy-6,8-dimethyl-1,7-naphthyridine-3-carboxylate

HRID 1070646

Reaction equation

HRID 1070646 reaction equation
[CH3:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[C:4]([CH3:9])[N:3]=1.C([O:12][CH:13]=[C:14]([C:20](OCC)=O)[C:15]([O:17][CH2:18][CH3:19])=[O:16])C>C1(C)C(C)=CC=CC=1>[OH:12][C:13]1[C:6]2[C:7](=[C:2]([CH3:1])[N:3]=[C:4]([CH3:9])[CH:5]=2)[N:8]=[CH:20][C:14]=1[C:15]([O:17][CH2:18][CH3:19])=[O:16]

Participants

4

Reactant 2

HCID 6871Diethyl (ethoxymethylene)malonateHCID 769642,6-Dimethyl-3-pyridylamine

Product 1

HCID 22397159Ethyl 4-Hydroxy-6,8-dimethyl-1,7-naphthyridine-3-carboxylateYield 30%

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

A mixture of 2,6-dimethyl-3-aminopyridine (0.85 g) and diethyl ethoxymethylenemalonate (1.53 g) is heated at 135° C. in xylene (30 mL) for 2 h allowing for removal of ethanol. After the solvent is removed, the mixture is suspended in diphenyl ether (15 mL). The mixture is then heated to reflux with removal of ethanol for 30 min. The reaction mixture is cooled to room temperature and hexanes (20 mL) is added. The resulting precipitate is filtered, washed with diethyl ether (2×10 mL) and dried to give 0.5 g (30%) of the title compound as a brown solid. Physical chracteristics: MS (ESI+) m/z 247 (M+H)+; 1H NMR (DMSO) δ8.67, 7.97, 4.38, 2.85, 2.67, 1.40.

Workup

  1. customallowing for removal of ethanol
  2. customAfter the solvent is removed
  3. temperatureThe mixture is then heated
  4. temperatureto reflux with removal of ethanol for 30 min
  5. additionhexanes (20 mL) is added
  6. filtrationThe resulting precipitate is filtered
  7. washwashed with diethyl ether (2×10 mL)
  8. customdried

Sources & evidence

ORD record
ord-5a6afead07e946eebdff6669cdb69237
Source dataset
uspto-grants-2005_06
Patent number
US06903097B2

Linked notes

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