Sulfuric Acid → 4-Methoxy-3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridine

HRID 924399Notes

Reaction equation

HRID 924399 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][N:6]=[C:5]2[CH2:9][CH2:10][CH2:11][C:4]=12.S(=O)(=O)(O)O.[N+:17]([O-])([O-:19])=[O:18].[K+].[OH-].[Na+]>>[CH3:1][O:2][C:3]1[C:8]([N+:17]([O-:19])=[O:18])=[CH:7][N:6]=[C:5]2[CH2:9][CH2:10][CH2:11][C:4]=12

Participants

5

Reactant 4

HCID 1118Sulfuric Acid2×HCID 14798Sodium HydroxideHCID 24434Potassium NitrateHCID 867266834-Methoxy-6,7-dihydro-5H-cyclopenta[b]pyridine

Product 1

HCID 867266844-Methoxy-3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridineYield 41.4%

Conditions

Temperature
80 °C

Procedure

4-Methoxy-6,7-dihydro-5H-cyclopenta[b]pyridine (2.90 g, 19.4 mmol) was mixed with concentrated sulfuric acid (17.0 g, 173 mmol) at 0° C., then a mixture of potassium nitrate (5.3 g, 52 mmol) in another portion of concentrated sulfuric acid (26.5 g, 270 mmol) was added slowly. The reaction mixture was heated at 80° C. for 4 h. The crude mixture was slowly poured into ice (50 g), and neutralized carefully with 50% NaOH solution to pH 8-9. The resulting mixture was extracted six times with EtOAc. The organic extracts were combined, dried and concentrated under reduced pressure to give the sub-title compound as a brown gum (1.56 g, 41%). LCMS calc. for C9H11N2O3 (M+H)+: m/z=195.3. Found: 195.2.

Workup

  1. additionwas added slowly
  2. extractionThe resulting mixture was extracted six times with EtOAc
  3. customdried
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-29465543df1a4c1eb89c56dd3650226d
Source dataset
uspto-grants-2016_03
Patent number
US09278950B2

Reaction notes

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