Phosphorus oxychloride → 4-Chloro-3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridine

HRID 924401Notes

Reaction equation

HRID 924401 reaction equation
[N+:1]([C:4]1[C:5](O)=[C:6]2[CH2:12][CH2:11][CH2:10][C:7]2=[N:8][CH:9]=1)([O-:3])=[O:2].P(Cl)(Cl)([Cl:16])=O>>[Cl:16][C:5]1[C:4]([N+:1]([O-:3])=[O:2])=[CH:9][N:8]=[C:7]2[CH2:10][CH2:11][CH2:12][C:6]=12

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 1785267573-Nitro-6,7-dihydro-5H-cyclopenta[b]pyridin-4-ol

Product 1

HCID 867266864-Chloro-3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridineYield 52.2%

Procedure

A solution of 3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridin-4-ol (1.424 g, 7.904 mmol) in phosphoryl chloride (11.0 mL, 118 mmol) was heated at 110° C. in a sealed flask under nitrogen for 2 h. The mixture was cooled to room temperature, and concentrated under reduced pressure. The residue was carefully quenched with ice, and neutralized with 50% aq. NaOH to pH 7. The resulting mixture was extracted three times with EtOAc, dried, filtered and concentrated under reduced pressure to give the sub-title compound as a brown solid (0.82 g, 52%). LCMS calc. for C8H8N2O2(M+H)+: m/z=199.3. Found: 199.2.

Workup

  1. concentrationconcentrated under reduced pressure
  2. customThe residue was carefully quenched with ice
  3. extractionThe resulting mixture was extracted three times with EtOAc
  4. customdried
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-9263c5f872a844058cd9c371797a6fd6
Source dataset
uspto-grants-2016_03
Patent number
US09278950B2

Reaction notes

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