Phosphorus pentachloride → 2-Methylquinazolin-5-amine

HRID 2118072Notes

Reaction equation

HRID 2118072 reaction equation
[CH3:1][C:2]1[NH:11][C:10](=O)[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][C:8]=2[N+:13]([O-])=O)[N:3]=1.P(Cl)(Cl)(Cl)(Cl)Cl.C([O-])(O)=O.[Na+]>P(Cl)(Cl)(Cl)=O.[Pd]>[NH2:13][C:8]1[CH:7]=[CH:6][CH:5]=[C:4]2[C:9]=1[CH:10]=[N:11][C:2]([CH3:1])=[N:3]2

Participants

6

Reactant 3

HCID 24819Phosphorus pentachlorideHCID 516892Sodium BicarbonateHCID 136342146HCID 136342146, compound

Product 1

HCID 179850582-Methylquinazolin-5-amineYield 5.4%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 24813Phosphorus oxychlorideSolvent

Procedure

12.7 g (mmol) of 2-methyl-5-nitro-3H-quinazolin-4-one (M. T. Bogert, V. J. Chambers J. Org. Chem. 1905, 649-658) and 37.5 g of phosphorus pentachloride are refluxed in 75 ml of phosphoryl chloride over 20 hours. After cooling, it is poured into saturated NaHCO3 solution and extracted with ethyl acetate. The organic phase is dried, and the solvent is removed. 14 g of 4-chloro-2-methyl-5-nitroquinazoline, of which 4.5 g (20.2 mmol) in 225 ml of ethyl acetate and 22.5 ml of triethylamine are dissolved, is obtained. 2 g of palladium on carbon is added, and it is stirred for four hours under hydrogen atmosphere at normal pressure while being cooled with ice. Catalyst is removed from the solution by means of filtration over Celite, whereby it is rewashed with 200 ml of ethanol and concentrated by evaporation. After chromatography on silica gel with ethyl acetate-ethanol (0-10%), 530 mg of the product is obtained.

Workup

  1. temperatureAfter cooling
  2. extractionextracted with ethyl acetate
  3. customThe organic phase is dried
  4. customthe solvent is removed
  5. dissolution14 g of 4-chloro-2-methyl-5-nitroquinazoline, of which 4.5 g (20.2 mmol) in 225 ml of ethyl acetate and 22.5 ml of triethylamine are dissolved
  6. customis obtained
  7. temperaturewhile being cooled with ice
  8. customCatalyst is removed from the solution by means of filtration over Celite, whereby it
  9. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-08d9d3f459044e61ac4326a2440f908e
Source dataset
uspto-grants-2008_10
Patent number
US07442794B2

Reaction notes

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