2,2-Dimethyl-1,3-dioxane-4,6-dione → 1,3-Dioxane-4,6-dione, 5-[[(6-methoxy-3-pyridinyl)amino]methylene]-2,2-dimethyl-

HRID 1725340Notes

Reaction equation

HRID 1725340 reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]([O:8][CH3:9])=[N:6][CH:7]=1.[CH3:10][C:11]1([CH3:19])[O:16][C:15](=[O:17])[CH2:14][C:13](=[O:18])[O:12]1.[CH2:20](OC(OCC)OCC)C>C(O)C>[CH3:9][O:8][C:5]1[N:6]=[CH:7][C:2]([NH:1][CH:20]=[C:14]2[C:15](=[O:17])[O:16][C:11]([CH3:19])([CH3:10])[O:12][C:13]2=[O:18])=[CH:3][CH:4]=1

Participants

5

Reactant 3

HCID 162492,2-Dimethyl-1,3-dioxane-4,6-dioneHCID 31214Ethyl orthoformateHCID 811216-Methoxy-3-pyridinylamine

Product 1

HCID 42557991,3-Dioxane-4,6-dione, 5-[[(6-methoxy-3-pyridinyl)amino]methylene]-2,2-dimethyl-

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 5-amino-2-methoxypyridine (50 g, 0.4 mol) in ethanol (300 ml) was treated with 2,2-dimethyl-[1,3]dioxane-4,6-dione (Meldrum's acid) (68 g) and triethylorthoformate (66 ml). The mixture was heated to reflux for 2 hours, then allowed to cool. Filtration afforded the intermediate 5-[(6-methoxy-pyridin-3-ylamino)-methylene]-2,2-dimethyl-[1,3]dioxane-4,6-dione as a white solid (101.2 g). A portion of this material (50 g) was added to boiling Dowtherm A (300 ml) over 3 minutes under a stream of argon. The mixture was refluxed for a further 5 minutes then allowed to cool before adding to ether. Filtration and drying afforded 6-methoxy-1H-[1,5]naphthyridin-4-one as a white solid (24.7 g, 70%).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 2 hours
  3. temperatureto cool
  4. filtrationFiltration

Sources & evidence

ORD record
ord-4d8ce20c47fd41e194ff33b16df296e8
Source dataset
uspto-grants-2009_02
Patent number
US07491714B2

Reaction notes

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