Potassium Nitrate → Ethyl 1-cyclopropyl-8-difluoromethoxy-6,7-difluoro-5-nitro-1,4-dihydro-4-oxoquinoline-3-carboxylate

HRID 2356381Notes

Reaction equation

HRID 2356381 reaction equation
[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][C:10]([F:19])=[C:11]([F:18])[C:12]=3[O:14][CH:15]([F:17])[F:16])[C:7](=[O:20])[C:6]([C:21]([O:23][CH2:24][CH3:25])=[O:22])=[CH:5]2)[CH2:3][CH2:2]1.[N+:26]([O-])([O-:28])=[O:27].[K+]>S(=O)(=O)(O)O>[CH:1]1([N:4]2[C:13]3[C:8](=[C:9]([N+:26]([O-:28])=[O:27])[C:10]([F:19])=[C:11]([F:18])[C:12]=3[O:14][CH:15]([F:16])[F:17])[C:7](=[O:20])[C:6]([C:21]([O:23][CH2:24][CH3:25])=[O:22])=[CH:5]2)[CH2:2][CH2:3]1

Participants

4

Reactant 2

HCID 24434Potassium NitrateHCID 15023786Ethyl 1-cyclopropyl-8-(difluoromethoxy)-6,7-difluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate

Product 1

HCID 15023843Ethyl 1-cyclopropyl-8-difluoromethoxy-6,7-difluoro-5-nitro-1,4-dihydro-4-oxoquinoline-3-carboxylateYield 45.5%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

The preparation comprises dissolving ethyl 1-cyclopropyl-6,7-difluoro-8-difluoromethoxyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (target product of embodiment 3, 1.0 g, 2.8 mmol) in concentrated sulfuric acid (10 mL), slowly adding potassium nitrate (2.0 g, 19.8 mmol), reacting for 1 h at 40° C., cooling down to room temperature, charging the reaction mixture into ice water (100 mL), stirring, filtering, treating obtained filter cake with ethanol (20 mL), refluxing for 0.5 h, cooling down to room temperature, filtering, and drying obtained filter cake to give ethyl 1-cyclopropyl-6,7-difluoro-8-difluoromethoxyl-5-nitro-1,4-dihydro-4-oxoquinoline-3-carboxylate (0.5 g, 45.5%).

Workup

  1. filtrationfiltering
  2. additiontreating
  3. customobtained
  4. filtrationfilter cake with ethanol (20 mL)
  5. temperaturerefluxing for 0.5 h
  6. temperaturecooling down to room temperature
  7. filtrationfiltering
  8. customdrying
  9. customobtained
  10. filtrationfilter cake

Sources & evidence

ORD record
ord-d09be2c50fb446f59963350ceb3728e1
Source dataset
uspto-grants-2010_07
Patent number
US07759362B2

Reaction notes

Loading…