Methyl chloroformate → 4H-Pyrido(1,2-a)pyrimidine-3-carboxamide, 4-oxo-N-propyl-

HRID 273717Notes

Reaction equation

HRID 273717 reaction equation
[O:1]=[C:2]1[N:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]2=[N:5][CH:4]=[C:3]1[C:12]([OH:14])=O.C(N(CC)CC)C.ClC(OC)=O.[CH2:27]([NH2:30])[CH2:28][CH3:29]>C(Cl)(Cl)Cl>[CH2:27]([NH:30][C:12]([C:3]1[C:2](=[O:1])[N:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]2=[N:5][CH:4]=1)=[O:14])[CH2:28][CH3:29]

Participants

6

Reactant 4

HCID 6586Methyl chloroformateHCID 7852PropylamineHCID 8471TriethylamineHCID 2915304-Oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid

Product 1

HCID 30792904H-Pyrido(1,2-a)pyrimidine-3-carboxamide, 4-oxo-N-propyl-Yield 81.2%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent3×

Procedure

A mixture containing 7.2 g (0.0378 mol) of 4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid and 6.2 g (0.044 mol) of triethylamine in 240 ml of chloroform is cooled below -10° C. by ice-salt. A solution of 3.25 ml (0.044 mol) of methyl chloroformate dissolved in 20 ml of chloroform is dropped to the above mixture at -20° C. during 20 minutes. After stirring for 5 minutes, 2.6 g (0.04 mol) of n-propylamine dissolved in 80 ml of chloroform are dropped at -18° C. during 60 minutes. The reaction mixture is stirred for 1 hour at the same temperature, then allowed to stand overnight under cooling by ice. For working up, the reaction mixture is washed 3 times with 70 ml of 5% sodium hydrogen carbonate solution each, then 3 times with 70 ml of water each. The organic phase is dried over anhydrous sodium sulfate, filtered and evaporated to yield 7.1 g (77.5%) of the named compound as light yellow crystals after recrystallization from ethanol, m.p.: 120°-122° C.

Workup

  1. additionis dropped to the above mixture at -20° C. during 20 minutes
  2. additionare dropped at -18° C. during 60 minutes
  3. stirringThe reaction mixture is stirred for 1 hour at the same temperature
  4. waitto stand overnight
  5. temperatureunder cooling by ice
  6. washthe reaction mixture is washed 3 times with 70 ml of 5% sodium hydrogen carbonate solution each, then 3 times with 70 ml of water each
  7. dry with materialThe organic phase is dried over anhydrous sodium sulfate
  8. filtrationfiltered
  9. customevaporated

Sources & evidence

ORD record
ord-f0f9dfa4a46440c4b46a5583989f9769
Source dataset
uspto-grants-1995_02
Patent number
US05387588

Reaction notes

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