p-Toluenesulfonic acid → 3-methoxy-1,7-naphthyridin-8(7H)-one

HRID 930482Notes

Reaction equation

HRID 930482 reaction equation
CO[CH:3](OC)[CH2:4][C:5]1[C:6]([C:13]([NH2:15])=[O:14])=[N:7][CH:8]=[C:9]([O:11][CH3:12])[CH:10]=1.CC1C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:12][O:11][C:9]1[CH:8]=[N:7][C:6]2[C:13](=[O:14])[NH:15][CH:3]=[CH:4][C:5]=2[CH:10]=1

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 867322863-(2,2-Dimethoxyethyl)-5-methoxypicolinamide

Product 1

HCID 867322883-methoxy-1,7-naphthyridin-8(7H)-oneYield 92%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a mixture of 3-(2,2-dimethoxyethyl)-5-methoxypicolinamide (6.74 g, 28.1 mmol) in toluene (112 ml) was added 4-methylbenzene sulfonic acid (monohydrate; 0.534 g, 2.81 mmol). The reaction mixture was heated to reflux for 20 h. The reaction mixture was cooled to rt and concentrated in vacuo to a volume of ca. 15 mL. The residue was triturated with heptanes and filtered to afford 3-methoxy-1,7-naphthyridin-8(7H)-one (4.53 g, 25.7 mmol, 92% yield) as a crude, tan solid that was advanced without further purification. Crude LCMS showed complete conversion to product MS m/z=177.1 [M+H]

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 20 h
  3. concentrationconcentrated in vacuo to a volume of ca. 15 mL
  4. customThe residue was triturated with heptanes
  5. filtrationfiltered

Sources & evidence

ORD record
ord-2835b9766c7c447684a9e641688e64ff
Source dataset
uspto-grants-2016_03
Patent number
US09296734B2

Reaction notes

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