Acetyl chloride → 1-Ethyl-2-methyl-5,6-diphenyl-1H-imidazo[4,5-b]pyrazine

HRID 1578462Notes

Reaction equation

HRID 1578462 reaction equation
Cl[C:2]1[C:7]([NH:8][CH2:9][CH3:10])=[N:6][C:5]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[C:4]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[N:3]=1.[CH2:23]([N:25](CC)CC)[CH3:24].C(Cl)(=O)C>C1C=CC=CC=1>[CH2:9]([N:8]1[C:7]2=[N:6][C:5]([C:11]3[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=3)=[C:4]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)[N:3]=[C:2]2[N:25]=[C:23]1[CH3:24])[CH3:10]

Participants

5

Reactant 3

HCID 6367Acetyl chlorideHCID 8471TriethylamineHCID 214548043-Chloro-N-ethyl-5,6-diphenyl-2-pyrazinamine

Product 1

HCID 214547901-Ethyl-2-methyl-5,6-diphenyl-1H-imidazo[4,5-b]pyrazine

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Conditions

Temperature
15 °C

Procedure

2-Chloro-3-ethylamino-5,6-diphenylpyrazine, (3.10 g, 0.01 moles) is dissolved in benzene (50 ml) and then triethylamine (1.29 g, 0.013 moles) and acetyl chloride (1.00 g, 0.013 moles) are added. The solution is refluxed 41/2 hours, cooled to 15°C and filtered. The filtrate is diluted with ethanol (3ml), warmed briefly at 50°C and then all volatile materials evaporated. The resultant brown oil is treated with liquid ammonia (17 g) in ethanol (60 ml) in a bomb at 165°C for 12 hours. The solution is diluted with water (200 ml), cooled and the yellow precipitate filtered off. The solid is triturated with boiling 50% aqueous methanol, filtered, and the filtrate chilled. The product is collected by filtration. Yield 0.45 g (14%). It is recrystallized from benzene-heptane, m.p. 178.5°-180°C.

Workup

  1. temperatureThe solution is refluxed 41/2 hours
  2. filtrationfiltered
  3. additionThe filtrate is diluted with ethanol (3ml)
  4. temperaturewarmed briefly at 50°C
  5. customall volatile materials evaporated
  6. additionThe resultant brown oil is treated with liquid ammonia (17 g) in ethanol (60 ml) in a bomb at 165°C for 12 hours
  7. additionThe solution is diluted with water (200 ml)
  8. temperaturecooled
  9. filtrationthe yellow precipitate filtered off
  10. customThe solid is triturated
  11. filtrationfiltered
  12. temperaturethe filtrate chilled
  13. filtrationThe product is collected by filtration
  14. customIt is recrystallized from benzene-heptane, m.p. 178.5°-180°C.

Sources & evidence

ORD record
ord-b6a7acafa9e74d029e7540a091576da1
Source dataset
uspto-grants-1976_02
Patent number
US03936308

Reaction notes

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