Phosphorus oxychloride → Benzonitrile, 4-(5,6,7,8-tetrahydroimidazo(1,5-a)pyridin-5-yl)-, hydrochloride (1:1)

HRID 568531Notes

Reaction equation

HRID 568531 reaction equation
[C:1]([C:4]1[CH:9]=[CH:8][C:7]([CH:10]2[N:15]3[CH:16]=[N:17][CH:18]=[C:14]3[CH2:13][CH2:12][CH2:11]2)=[CH:6][CH:5]=1)(=O)[NH2:2].P(Cl)(Cl)([Cl:21])=O>C(Cl)(Cl)Cl>[ClH:21].[C:1]([C:4]1[CH:5]=[CH:6][C:7]([CH:10]2[N:15]3[CH:16]=[N:17][CH:18]=[C:14]3[CH2:13][CH2:12][CH2:11]2)=[CH:8][CH:9]=1)#[N:2]

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 136882214-(5,6,7,8-Tetrahydroimidazo[1,5-a]pyridin-5-yl)benzamide

Product 1

HCID 59694Benzonitrile, 4-(5,6,7,8-tetrahydroimidazo(1,5-a)pyridin-5-yl)-, hydrochloride (1:1)

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

A solution of 1.13 g of 5-(p-carbamoylphenyl)-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine and 1.0 ml of phosphorus oxychloride in 30 ml of chloroform is refluxed for 15 h, cooled and evaporated with toluene. The resulting oil is redissolved in 30 ml of methylene chloride, cooled to 0° and 30 ml of an ice-cold solution of 50% ammonium hydroxide solution is added. The organic phase is separated, dried and evaporated to an oil. Filtration through 20 g of silica with ethyl acetate yields the free title compound which is dissolved in 20 ml of acetone and treated with 1.2 ml of 3N ethereal hydrogen chloride to yield its hydrochloride, m.p. 209°-210°.

Workup

  1. temperaturecooled
  2. customevaporated with toluene
  3. dissolutionThe resulting oil is redissolved in 30 ml of methylene chloride
  4. temperaturecooled to 0°
  5. addition30 ml of an ice-cold solution of 50% ammonium hydroxide solution is added
  6. customThe organic phase is separated
  7. customdried
  8. customevaporated to an oil
  9. filtrationFiltration through 20 g of silica with ethyl acetate

Sources & evidence

ORD record
ord-b81577a872324566bdc32ba2be127c75
Source dataset
uspto-grants-1988_03
Patent number
US04728645

Reaction notes

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