3-Chloro-2-butanone → 8-Amino-2,3-dimethylimidazo[1,2-a]pyridine-6-carboxamide

HRID 2184301Notes

Reaction equation

HRID 2184301 reaction equation
[Na+].[Br-].Cl[CH:4]([CH3:8])[C:5](=O)[CH3:6].[NH2:9][C:10]1[C:11]([NH2:19])=[N:12][CH:13]=[C:14]([CH:18]=1)[C:15]([NH2:17])=[O:16]>C1(=O)CCCCC1>[NH2:9][C:10]1[C:11]2[N:12]([C:4]([CH3:8])=[C:5]([CH3:6])[N:19]=2)[CH:13]=[C:14]([C:15]([NH2:17])=[O:16])[CH:18]=1

Participants

5

Reactant 3

HCID 200263-Chloro-2-butanoneHCID 253881Sodium BromideHCID 99421905,6-Diaminonicotinamide

Product 1

HCID 98557898-Amino-2,3-dimethylimidazo[1,2-a]pyridine-6-carboxamideYield 117.3%

Reagents, catalysts & solvents 1

HCID 7967CyclohexanoneSolvent

Conditions

Temperature
80 °C

Procedure

NaBr (27.0 g; 0.259 mol; 1.33 equiv) was suspended in cyclohexanone (220 mL) and 3-chloro-2-butanone (25.7 mL; 0.242 mol; 1.24 equiv) was added in one portion. The mixture was heated to 80° C. and stirred for 3 h. The mixture was cooled to 50° C., the white solid was filtered off and washed with cyclohexanone (60 mL). 5,6-Diamino-nicotinamide (30 g; 0.1946 mol; 1.0 equiv) was added to the filtrate and the mixture was heated to 100° C. for 4 h, after which 98% conversion was determined by HPLC. The reaction mixture was cooled to 20° C., stirring was continued for 2 h at 20° C. The solid was filtered off, washed with TBME (220 mL) and dried to yield 46.6 g of the title compound. Yield: 73%.

Workup

  1. temperatureThe mixture was cooled to 50° C.
  2. filtrationthe white solid was filtered off
  3. washwashed with cyclohexanone (60 mL)
  4. temperaturethe mixture was heated to 100° C. for 4 h
  5. temperatureThe reaction mixture was cooled to 20° C.
  6. stirringstirring
  7. waitwas continued for 2 h at 20° C
  8. filtrationThe solid was filtered off
  9. washwashed with TBME (220 mL)
  10. customdried

Sources & evidence

ORD record
ord-80964c4f784a45f18191ca850486ed8c
Source dataset
uspto-grants-2005_05
Patent number
US06900324B2

Reaction notes

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