Phosphorus oxychloride → 1-Chloropyrrolo[1,2-a]pyrazine

HRID 2248593Notes

Reaction equation

HRID 2248593 reaction equation
[C:1]1(=O)[NH:6][CH:5]=[CH:4][N:3]2[CH:7]=[CH:8][CH:9]=[C:2]12.P(Cl)(Cl)([Cl:13])=O.C(=O)(O)[O-].[Na+]>>[Cl:13][C:1]1[C:2]2[N:3]([CH:7]=[CH:8][CH:9]=2)[CH:4]=[CH:5][N:6]=1

Participants

4

Reactant 3

HCID 24813Phosphorus oxychlorideHCID 516892Sodium BicarbonateHCID 15662088Pyrrolo[1,2-a]pyrazin-1(2H)-one

Product 1

HCID 156620891-Chloropyrrolo[1,2-a]pyrazineYield 71%

Procedure

To pyrrolo[1,2-a]pyrazin-1(2H)-one (0.35 g, 2.61 mmol) was added phosphorous oxychloride (4.0 g, 26.1 mmol). The reaction mixture was agitated for approximately 16 hours. The reaction mixture was then made alkaline by the addition of sodium bicarbonate. The reaction mixture was then extracted with hexane, washed with a saturated sodium bicarbonate solution, dried over MgSO4 and evaporated. The product was purified by recrystallization in hexane and cooled with a mixture of dry ice and acetone to give the title compound, 1-chloropyrrolo[1,2-a]pyrazine (71%), m.p. 56°-57° C.

Workup

  1. extractionThe reaction mixture was then extracted with hexane
  2. washwashed with a saturated sodium bicarbonate solution
  3. dry with materialdried over MgSO4
  4. customevaporated
  5. customThe product was purified by recrystallization in hexane
  6. temperaturecooled with a mixture of dry ice and acetone

Sources & evidence

ORD record
ord-5df843b4c39e4a0f9cb51d607ba6561f
Source dataset
uspto-grants-1991_08
Patent number
US05041442

Reaction notes

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