Hydrochloric Acid → 1-Cyclopropyl-5-methyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

HRID 232660Notes

Reaction equation

HRID 232660 reaction equation
[CH:1]1([N:4]2[C:13]3[C:8](=[C:9]([CH3:17])[C:10]([F:16])=[C:11]([F:15])[C:12]=3[F:14])[C:7](=[O:18])[C:6]([C:19]([O:21]CC)=[O:20])=[CH:5]2)[CH2:3][CH2:2]1.Cl>C(O)(=O)C>[CH:1]1([N:4]2[C:13]3[C:8](=[C:9]([CH3:17])[C:10]([F:16])=[C:11]([F:15])[C:12]=3[F:14])[C:7](=[O:18])[C:6]([C:19]([OH:21])=[O:20])=[CH:5]2)[CH2:2][CH2:3]1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 14651259Ethyl 1-cyclopropyl-6,7,8-trifluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate

Product 1

HCID 146512581-Cyclopropyl-5-methyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acidYield 92.6%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To ethyl 1-cyclopropyl-6,7,8-trifluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (4.10 g) are added 90% acetic acid--conc. hydrochloric acid (4:1, 81.25 ml) and the mixture is refluxed for 2 hours. After cooling, the precipitated crystals are isolated, washed with water, ethanol, and diethyl ether in this order to give 1-cyclopropyl-6,7,8-trifluoro-5-methyl-1,4,-dihydro-4-oxoquinoline-3-carboxylic acid (3.47 g), as white needles, m.p. 218°-220° C.

Workup

  1. temperatureAfter cooling
  2. customthe precipitated crystals are isolated
  3. washwashed with water, ethanol, and diethyl ether in this order

Sources & evidence

ORD record
ord-537e5a7ecd264dcea1b7291413d48274
Source dataset
uspto-grants-1997_01
Patent number
US05591744

Reaction notes

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