Cyclopentylamine → 4H-Pyrido(1,2-a)pyrimidine-3-carboxamide, N-cyclopentyl-6-methyl-4-oxo-

HRID 467017Notes

Reaction equation

HRID 467017 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([NH2:33])[CH2:32][CH2:31][CH2:30][CH2:29]1>C(Cl)(Cl)Cl>[CH:28]1([NH:33][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])[CH2:32][CH2:31][CH2:30][CH2:29]1

Participants

6

Reactant 4

HCID 2906CyclopentylamineHCID 6586Methyl chloroformateHCID 8471TriethylamineHCID 2084164H-Pyrido(1,2-a)pyrimidine-3-carboxylic acid, 6-methyl-4-oxo-

Product 1

HCID 30792844H-Pyrido(1,2-a)pyrimidine-3-carboxamide, N-cyclopentyl-6-methyl-4-oxo-Yield 65.9%

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, 7.49 g (0.088 mol) of cyclopentylamine 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., 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 yield 14.3 g (65.9%) of the named product as yellow crystals after recrystallization from ethanol, m.p.: 158°-160° C.

Workup

  1. temperatureis cooled below -10° C. by ice salt
  2. additionare dropped to the above solution at -15° C. during 30 minutes
  3. stirringThe reaction mixture is stirred for 1 hour below -10° C.
  4. waitto stand overnight
  5. temperatureunder cooling by ice
  6. 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
  7. dry with materialThe organic phase is dried over anhydrous sodium sulfate
  8. filtrationfiltered
  9. customevaporated

Sources & evidence

ORD record
ord-79ef32574d3541f19793964646ef0011
Source dataset
uspto-grants-1992_10
Patent number
US05158951

Reaction notes

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