Triethylamine → 2-(6-Chloro-2-pyrazinyl)-octahydro-2H-pyrido [1,2-a]pyrazine

HRID 1759239Notes

Reaction equation

HRID 1759239 reaction equation
[CH2:1]1[NH:6][CH2:5][CH2:4][N:3]2[CH2:7][CH2:8][CH2:9][CH2:10][CH:2]12.[Cl:11][C:12]1[CH:17]=[N:16][CH:15]=[C:14](Cl)[N:13]=1.C(N(CC)CC)C>C(#N)C>[Cl:11][C:12]1[N:13]=[C:14]([N:6]2[CH2:5][CH2:4][N:3]3[CH2:7][CH2:8][CH2:9][CH2:10][CH:2]3[CH2:1]2)[CH:15]=[N:16][CH:17]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 785042,6-DichloropyrazineHCID 2876391(+-)-1,4-Diazabicyclo[4.4.0]decane

Product 1

HCID 130345932-(6-Chloro-2-pyrazinyl)-octahydro-2H-pyrido [1,2-a]pyrazine

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A solution of octahydro-2H-pyrido[1,2-a]pyrazine (4 gm, 0.029 moles), 2,6-dichloropyrazine (4.28 gm, 0.029 moles) and triethylamine (8 ml. 0.06 moles) in 75 ml of acetonitrile is heated under reflux for 4 hours. After cooling, the precipitate is filtered off and washed with a little acetonitrile. The filtrate is concentrated under reduced pressure and the resulting residue is partitioned between water and ether. The aqueous layer is made basic with potassium carbonate and extracted 3 times with 100 ml. portions of ether. The combined ether layer is washed with saline and dried over sodium sulfate. After filtering off the drying agent the clear filtrate is made acidic with dry hydrogen chloride gas. The precipitate is filtered off, washed with ether and dried. After two crystallizations from ethanol there is obtained a 4.5 gm (54 percent) yield of title compound, m.p. 298°-301° C.

Workup

  1. temperatureunder reflux for 4 hours
  2. temperatureAfter cooling
  3. filtrationthe precipitate is filtered off
  4. washwashed with a little acetonitrile
  5. concentrationThe filtrate is concentrated under reduced pressure
  6. customthe resulting residue is partitioned between water and ether
  7. extractionextracted 3 times with 100 ml
  8. washThe combined ether layer is washed with saline
  9. dry with materialdried over sodium sulfate
  10. filtrationAfter filtering off the drying agent the clear filtrate
  11. filtrationThe precipitate is filtered off
  12. washwashed with ether
  13. customdried
  14. customAfter two crystallizations from ethanol

Sources & evidence

ORD record
ord-0c3a87e4f39e43b68d64bed99b03344c
Source dataset
uspto-grants-1982_07
Patent number
US04339579

Reaction notes

Loading…