Methyl chloroformate → 4H-Pyrido(1,2-a)pyrimidine-3-carboxamide, N-cyclopropyl-6-methyl-4-oxo-

HRID 1655912Notes

Reaction equation

HRID 1655912 reaction equation
[CH3:1][C:2]1[N:7]2[C:8](=[O:15])[C:9]([C:12]([OH:14])=O)=[CH:10][N:11]=[C:6]2[CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C.ClC(OC)=O.[CH:28]1([NH2:31])[CH2:30][CH2:29]1>C(Cl)(Cl)Cl>[CH:28]1([NH:31][C:12]([C:9]2[C:8](=[O:15])[N:7]3[C:2]([CH3:1])=[CH:3][CH:4]=[CH:5][C:6]3=[N:11][CH:10]=2)=[O:14])[CH2:30][CH2:29]1

Participants

6

Reactant 4

HCID 6586Methyl chloroformateHCID 8471TriethylamineHCID 69828CyclopropylamineHCID 2084164H-Pyrido(1,2-a)pyrimidine-3-carboxylic acid, 6-methyl-4-oxo-

Product 1

HCID 30792834H-Pyrido(1,2-a)pyrimidine-3-carboxamide, N-cyclopropyl-6-methyl-4-oxo-Yield 74.5%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent3×

Procedure

A mixture containing 16.32 g (0.08 mol) of 6-methyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acid and 12.4 ml (0.088 mol) of triethylamine in 480 ml of chloroform is cooled below -10° C. by ice-salt. A solution of 6.5 ml (0.08 mol) of methyl chloroformate dissolved in 40 ml of chloroform is dropped to the above mixture at a temperature between -10° C. and -17° C. during 25 minutes. After stirring for 5 minutes, 5.025 g (0.088 mol) of cyclopropylamine in 80 ml of chloroform are dropped to the above solution at the same temperature during 40 minutes. The reaction mixture is stirred for 1 hour below -10° C. and then allowed to stand overnight under cooling by ice. For working up, the reaction mixture is washed 3 times with 150 ml of 5% sodium hydrogen carbonate solution each, then 3 times with 150 ml of water each. The organic phase is dried over anhydrous sodium sulfate, filtered and evaporated to give 14.5 g (74.5%) of the named compound as light yellow crystals after recrystallization from ethanol, m.p.: 174°-176° C.

Workup

  1. additionis dropped to the above mixture at a temperature between -10° C. and -17° C. during 25 minutes
  2. stirringThe reaction mixture is stirred for 1 hour below -10° C.
  3. waitto stand overnight
  4. temperatureunder cooling by ice
  5. washthe reaction mixture is washed 3 times with 150 ml of 5% sodium hydrogen carbonate solution each, then 3 times with 150 ml of water each
  6. dry with materialThe organic phase is dried over anhydrous sodium sulfate
  7. filtrationfiltered
  8. customevaporated

Sources & evidence

ORD record
ord-8adc3672f7ab4ff080cd458ed45f298e
Source dataset
uspto-grants-1993_10
Patent number
US05252572

Reaction notes

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