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

HRID 1499442Notes

Reaction equation

HRID 1499442 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].O=P(Cl)(Cl)[Cl:16]>>[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%

Procedure

A solution of 3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridin-4-ol (1.424 g, 7.904 mmol) in POCl3 (11.0 mL) was heated at 110° C. in a sealed flask under N2 for 2 h. The crude mixture was cooled to room temperature, and concentrated under reduced pressure. The residue was carefully quenched with ice, and neutralized with 50% NaOH to pH 7. The resulting mixture was extracted with EtOAc three times. The combined organic layers were dried, filtered and concentrated under reduced pressure to give the crude sub-title compound as a brown solid (0.82 g, 52%), which was used without further purification. LCMS calc. for C8H8N2O2 (M+H)+: m/z=199.0. Found: 199.2.

Workup

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

Sources & evidence

ORD record
ord-aaf6ecf0d49949a99033db00232fb3a0
Source dataset
uspto-grants-2015_12
Patent number
US09200004B2

Reaction notes

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