Ethanol → Ethyl 4-hydroxy-6-methoxy-1,5-naphthyridine-3-carboxylate

HRID 1019853Notes

Reaction equation

HRID 1019853 reaction equation
C(O[C:4](=[O:21])[C:5](=[CH:11][NH:12][C:13]1[CH:14]=[N:15][C:16]([O:19][CH3:20])=[CH:17][CH:18]=1)[C:6]([O:8][CH2:9][CH3:10])=[O:7])C.C(O)C>C1(OC2C=CC=CC=2)C=CC=CC=1>[CH2:9]([O:8][C:6]([C:5]1[C:4](=[O:21])[C:14]2[C:13](=[CH:18][CH:17]=[C:16]([O:19][CH3:20])[N:15]=2)[NH:12][CH:11]=1)=[O:7])[CH3:10]

Participants

4

Reactant 2

HCID 702EthanolHCID 619151Diethyl 2-(((6-methoxypyridin-3-yl)amino)methylene)malonate

Product 1

HCID 600736Ethyl 4-hydroxy-6-methoxy-1,5-naphthyridine-3-carboxylateYield 32%

Reagents, catalysts & solvents 1

HCID 7583Diphenyl EtherSolvent

Conditions

Temperature
28 °C

Procedure

A solution of 2-[(6-methoxy-pyridin-3-ylamino)-methylene]-malonic acid diethyl ester (260.0 g, 1.365 mol, 1.0 eq) in diphenyl ether (500 mL) is heated to reflux. While the ethanol formed is removed by azeotropic distillation the reflux temperature reached 245° C. The reaction mixture is kept at 245° C. for 3 hours, then it is cooled to 28° C., a brown solid precipitated and is collected by filtration and washed with hexane (500 mL). The solid is dried under vacuum to afford 6-methoxy-4-oxo-1,4-dihydro-[1,5]naphthyridine-3-carboxylic acid ethyl ester as a brown powder (74.2 g, 32% yield).

Workup

  1. customis removed by azeotropic distillation the reflux temperature
  2. customreached 245° C
  3. customa brown solid precipitated
  4. filtrationis collected by filtration
  5. washwashed with hexane (500 mL)
  6. customThe solid is dried under vacuum

Sources & evidence

ORD record
ord-b0c8ecc22c3f428e996b18d9d6f722a5
Source dataset
uspto-grants-2014_05
Patent number
US08716280B2

Reaction notes

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