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

HRID 273713Notes

Reaction equation

HRID 273713 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([NH2:34])[CH2:33][CH2:32][CH2:31][CH2:30][CH2:29]1>C(Cl)(Cl)Cl>[CH:28]1([NH:34][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])[CH2:33][CH2:32][CH2:31][CH2:30][CH2:29]1

Participants

6

Reactant 4

HCID 6586Methyl chloroformateHCID 7965CyclohexylamineHCID 8471TriethylamineHCID 2084164H-Pyrido(1,2-a)pyrimidine-3-carboxylic acid, 6-methyl-4-oxo-

Product 1

HCID 30792854H-Pyrido(1,2-a)pyrimidine-3-carboxamide, N-cyclohexyl-6-methyl-4-oxo-Yield 73.2%

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 in 40 ml of chloroform is dropped to the above mixture at -10° C. during 20 minutes. After stirring for 5 minutes, 8.73 g (0.088 mol) of cyclohexylamine dissolved in 80 ml of chloroform are dropped to the above solution at -15° C. during 30 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 and then 3 times with 150 ml of water each. The organic phase is dried over anhydrous sodium sulfate, filtered and evaporated to give 16.7 g (73.2%) of the named product as yellow crystals after recrystallization from ethanol, m.p.: 174°-176° C.

Workup

  1. additionare dropped to the above solution at -15° C. during 30 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 and 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-8d8f9e9d1da048d9b2ab6946a381c02f
Source dataset
uspto-grants-1995_02
Patent number
US05387588

Reaction notes

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