Phosphorus sulfide (P2S5) → 8-Cyano-3-methyl-5,6,7,8-tetrahydroquinoline

HRID 2083427Notes

Reaction equation

HRID 2083427 reaction equation
[CH3:1][C:2]1[CH:3]=[N:4][C:5]2[CH:6]([C:12]([NH2:14])=O)[CH2:7][CH2:8][CH2:9][C:10]=2[CH:11]=1.P12(SP3(SP(SP(S3)(S1)=S)(=S)S2)=S)=S>N1C=CC=CC=1>[C:12]([CH:6]1[C:5]2[N:4]=[CH:3][C:2]([CH3:1])=[CH:11][C:10]=2[CH2:9][CH2:8][CH2:7]1)#[N:14]

Participants

4

Reactant 2

HCID 14817Phosphorus sulfide (P2S5)HCID 122782273-Methyl-5,6,7,8-tetrahydroquinoline-8-carboxamide

Product 1

HCID 122782108-Cyano-3-methyl-5,6,7,8-tetrahydroquinolineYield 52.2%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

3-Methyl-5,6,7,8-tetrahydroquinoline-8-carboxamide (3.6g.) in pyridine (54 ml.) was treated with P2S5 (7.56 g.) and the mixture heated at reflux with stirring for 3 hours. The solvent was removed under reduced pressure and the residue cooled in ice-water then made basic with 10% NaOH. The basic solution was extracted with chloroform (3 times) and the combined extracts extracted with 2NHCl (twice). The combined acid extracts were basified with solid sodium carbonate and extracted into chloroform (3 times). The combined chloroform extracts were washed with brine dried (MgSO4) and evaporated to give the title compound 1.7 g. This was converted to the hydrochloride by dissolving in ether and adding ethereal HCl. An oily residue was formed from which the supernatent liquid was decanted. The residue was triturated twice with dry ether and the remaining solid recrystallised from isopropyl alcohol giving the hydrochloride of the title compound m.p. 189° C.

Workup

  1. temperaturethe mixture heated
  2. temperatureat reflux
  3. customThe solvent was removed under reduced pressure
  4. temperaturethe residue cooled in ice-water
  5. extractionThe basic solution was extracted with chloroform (3 times)
  6. extractionthe combined extracts extracted with 2NHCl (twice)
  7. extractionextracted into chloroform (3 times)
  8. washThe combined chloroform extracts were washed with brine
  9. dry with materialdried (MgSO4)
  10. customevaporated

Sources & evidence

ORD record
ord-f4448432a8774578870be4f6e4dd93d0
Source dataset
uspto-grants-1978_04
Patent number
US04085215

Reaction notes

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