Hydrochloric Acid → 1-Cyclopropyl-6,7-difluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

HRID 2351894Notes

Reaction equation

HRID 2351894 reaction equation
[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][C:10]([F:16])=[C:11]([F:15])[C:12]=3[CH3:14])[C:7](=[O:17])[C:6]([C:18]([O:20]CC)=[O:19])=[CH:5]2)[CH2:3][CH2:2]1.Cl.O>C(O)(=O)C>[CH:1]1([N:4]2[C:13]3[C:8](=[CH:9][C:10]([F:16])=[C:11]([F:15])[C:12]=3[CH3:14])[C:7](=[O:17])[C:6]([C:18]([OH:20])=[O:19])=[CH:5]2)[CH2:2][CH2:3]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 962WaterHCID 9839540Ethyl 1-cyclopropyl-6,7-difluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate

Product 1

HCID 140525751-Cyclopropyl-6,7-difluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acidYield 90%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To ethyl 1-cyclopropyl-6,7-difluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (2.2 g) are added conc. hydrochloric acid (5 ml), water (2 ml) and acetic acid (20 ml), and the mixture is refluxed for 2 hours. After cooling, the precipitated crystals are separated by filtration, and washed with water, ethanol and diethyl ether in this order to give 1-cyclopropyl-6,7-difluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (1.8 g) as a white crystal, m.p. 240°-243° C.

Workup

  1. temperaturethe mixture is refluxed for 2 hours
  2. temperatureAfter cooling
  3. customthe precipitated crystals are separated by filtration
  4. washwashed with water, ethanol and diethyl ether in this order

Sources & evidence

ORD record
ord-31f8b4bf514244c4a965db72126a8b3d
Source dataset
uspto-grants-1989_10
Patent number
US04874764

Reaction notes

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