Ethyl orthoformate → 7-Aminopyrido[4,3-d]pyrimidin-4(3H)-one

HRID 2287683Notes

Reaction equation

HRID 2287683 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([NH2:8])[N:5]=[CH:4][C:3]=1[C:9]([NH2:11])=[O:10].[CH:12](OCC)(OCC)OCC>>[NH2:8][C:6]1[N:5]=[CH:4][C:3]2[C:9](=[O:10])[NH:11][CH:12]=[N:1][C:2]=2[CH:7]=1

Participants

3

Reactant 2

HCID 31214Ethyl orthoformateHCID 6433944,6-Diaminonicotinamide

Product 1

HCID 1354805187-Aminopyrido[4,3-d]pyrimidin-4(3H)-one

Procedure

Crude 4,6-diamino-3-pyridylcarboxamide (9.2 g) is heated in purified (EtO)3CH (distilled from Na, 60 mL) at 170° C. for 1.5 d. After removing the solvent, the residue is dissolved in hot 2M NaOH, filtered, neutralized (conc. HCl) and cooled to give 7-amino-4-oxo-3H-pyrido[4,3-d]pyrimidine (3.57 g, 69% from the nitrile) as a light brown solid. 1H NMR (DMSO) δ 11.79 (1H, brs), 8.74 (1H, s), 7.97 (1H, s), 6.76 (2H, brs), 6.38 (1H, s).

Workup

  1. customAfter removing the solvent
  2. dissolutionthe residue is dissolved in hot 2M NaOH
  3. filtrationfiltered
  4. temperaturecooled

Sources & evidence

ORD record
ord-7a40987262274171af27b1bc5320f9ba
Source dataset
uspto-grants-2000_07
Patent number
US06084095

Reaction notes

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