Methyl chloroformate → 4H-Pyrido(1,2-a)pyrimidine-3-carboxamide, 9-methyl-4-oxo-N-propyl-

HRID 273720Notes

Reaction equation

HRID 273720 reaction equation
[CH3:1][C:2]1[C:7]2=[N:8][CH:9]=[C:10]([C:13]([OH:15])=O)[C:11](=[O:12])[N:6]2[CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C.ClC(OC)=O.[CH2:28]([NH2:31])[CH2:29][CH3:30]>C(Cl)(Cl)Cl>[CH2:28]([NH:31][C:13]([C:10]1[C:11](=[O:12])[N:6]2[CH:5]=[CH:4][CH:3]=[C:2]([CH3:1])[C:7]2=[N:8][CH:9]=1)=[O:15])[CH2:29][CH3:30]

Participants

6

Reactant 4

HCID 6586Methyl chloroformateHCID 7852PropylamineHCID 8471TriethylamineHCID 167860819-Methyl-4H-Pyrido[1,2-a]pyrimidine-4-oxo-3-carboxylic acid

Product 1

HCID 30792934H-Pyrido(1,2-a)pyrimidine-3-carboxamide, 9-methyl-4-oxo-N-propyl-Yield 70.7%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent3×

Procedure

A mixture containing 9.2 g (0.045 mol) of 9-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid and 7.05 ml (0.05 mol) of triethylamine in 280 ml of chloroform is cooled below -10° C. by ice-salt. A solution of 3.7 ml (0.045 mol) of methyl chloroformate dissolved in 25 ml of chloroform is dropped to the above mixture at -21° C. during 10 minutes. After stirring for 5 minutes, 2.95 g (0.05 mol) of propylamine dissolved in 50 ml of chloroform are dropped to the above solution at a temperature between -21° C. and -19° C. during 45 minutes. The reaction mixture is stirred below -10° C. for 1 hour, 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 give 7.8 g (70.7%) of the named compound as snow-white crystals after recrystallization from ethanol, m.p.: 138°-140° C.

Workup

  1. additionis dropped to the above mixture at -21° C. during 10 minutes
  2. additionare dropped to the above solution at a temperature between -21° C. and -19° C. during 45 minutes
  3. stirringThe reaction mixture is stirred below -10° C. for 1 hour
  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-7dea5289d2eb42dcb6d13e672c4879d4
Source dataset
uspto-grants-1995_02
Patent number
US05387588

Reaction notes

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