Sulfuric Acid → Ethyl 6,7-difluoro-1-(2-fluoroethyl)-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylate

HRID 358889Notes

Reaction equation

HRID 358889 reaction equation
[F:1][C:2]1[C:3]([O:13][CH3:14])=[C:4]([CH:9]=[CH:10][C:11]=1[F:12])[NH:5][CH2:6][CH2:7][F:8].C([O:17][CH:18]=[C:19]([C:25](OCC)=O)[C:20]([O:22][CH2:23][CH3:24])=[O:21])C.C(OC(=O)C)(=O)C.S(=O)(=O)(O)O>>[F:12][C:11]1[CH:10]=[C:9]2[C:4](=[C:3]([O:13][CH3:14])[C:2]=1[F:1])[N:5]([CH2:6][CH2:7][F:8])[CH:25]=[C:19]([C:20]([O:22][CH2:23][CH3:24])=[O:21])[C:18]2=[O:17]

Participants

5

Reactant 4

HCID 1118Sulfuric AcidHCID 6871Diethyl (ethoxymethylene)malonateHCID 7918Acetic AnhydrideHCID 20067124HCID 20067124, compound

Product 1

HCID 20067126Ethyl 6,7-difluoro-1-(2-fluoroethyl)-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylateYield 24.8%

Procedure

A mixture of the whole (0.0022 mole) of the 3,4-difluoro-N-(2-fluoroethyl)-2-methoxyaniline prepared as described in step (C3) and 0.57 g (0.0026 mole) of diethyl ethoxymethylenemalonate was heated at 140°-150° C. for 6 hours, after which it was allowed to cool to room temperature. 2 ml of acetic anhydride and 1 ml of concentrated sulfuric acid were added in that order to the mixture, and it was then allowed to stand at room temperature. The reaction mixture was then poured into ice-water to precipitate crystals, which were collected by filtration to give 0.18 g of ethyl 6,7-difluoro-1-(2-fluoroethyl)-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylate (X, R9' =2-fluoroethyl) as colorless crystals.

Workup

  1. customprepared
  2. temperaturewas heated at 140°-150° C. for 6 hours
  3. customto stand at room temperature
  4. customto precipitate crystals, which
  5. filtrationwere collected by filtration

Sources & evidence

ORD record
ord-e9c73ec8742646689a09ef251a4ae11b
Source dataset
uspto-grants-1991_03
Patent number
US04997943

Reaction notes

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