Hydrochloric Acid → Ibafloxacin

HRID 1381278Notes

Reaction equation

HRID 1381278 reaction equation
[F:1][C:2]1[C:3]([CH3:13])=[C:4]2[C:9](=[CH:10][CH:11]=1)[NH:8][CH:7]([CH3:12])[CH2:6][CH2:5]2.C([O:16][CH:17]=[C:18]([C:24](OCC)=O)[C:19]([O:21]CC)=[O:20])C.Cl>[OH-].[Na+]>[CH3:12][CH:7]1[N:8]2[C:9]3[C:10](=[CH:11][C:2]([F:1])=[C:3]([CH3:13])[C:4]=3[CH2:5][CH2:6]1)[C:17](=[O:16])[C:18]([C:19]([OH:21])=[O:20])=[CH:24]2

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 6871Diethyl (ethoxymethylene)malonateHCID 136692466-Fluoro-2,5-dimethyl-1,2,3,4-tetrahydroquinoline

Product 1

HCID 71186Ibafloxacin

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 9.3 g of 6-fluoro-5-methyl-1,2,3,4-tetrahydroquinaldine and 17 ml of diethyl ethoxymethylenemalonate was heated at 150°-160° C. for 3.5 hours, and then cooled to 100° C. To this solution was added 56 g of polyphosphoric acid, and the mixture was stirred for one hour while heating on a steam bath. The mixture was then cooled to room temperature and allowed to stand for about 72 hours. To this mixture, containing ethyl 1,2-dihydro-5,8-dimethyl-9-fluoro-1-oxo-1H,5H-benzo[ij]quinolizine-2-carboxylate, was added 250 ml of 20% aqueous sodium hydroxide to make the solution basic. The solution was then heated at its reflux temperature for 2 hours, cooled, and acidified with concentrated hydrochloric acid. The solid was separated by filtration and recrystallized from aqueous N,N-dimethylformamide. Washing with ethanol followed by drying provided 6,7-dihydro-5,8-dimethyl-9- fluoro-1-oxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid as an off-white solid, m.p. 269-272° C. Analysis: Calculated for C15H14FNO3: %C, 65.4; %H, 5.1; %N, 5.1; Found: %C, 65.0; %H, 5.0; %N, 5.0.

Workup

  1. temperaturewas heated at 150°-160° C. for 3.5 hours
  2. temperaturewhile heating on a steam bath
  3. temperatureThe mixture was then cooled to room temperature
  4. waitto stand for about 72 hours
  5. temperatureThe solution was then heated at its
  6. temperaturereflux temperature for 2 hours
  7. temperaturecooled
  8. customThe solid was separated by filtration
  9. customrecrystallized from aqueous N,N-dimethylformamide
  10. washWashing with ethanol
  11. customby drying

Sources & evidence

ORD record
ord-a2276bc5891c422ca199a13c047eced6
Source dataset
uspto-grants-1986_04
Patent number
US04585868

Reaction notes

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