Sulfuric Acid → Ethyl 1-cyclopropyl-7-(4-ethoxycarbonyl-1-piperazinyl)-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate

HRID 1638670Notes

Reaction equation

HRID 1638670 reaction equation
[CH:1]1([N:4]([CH:27]=[C:28]([C:34](OCC)=[O:35])[C:29]([O:31][CH2:32][CH3:33])=[O:30])[C:5]2[C:10]([N+]([O-])=O)=[CH:9][C:8]([F:14])=[C:7]([N:15]3[CH2:20][CH2:19][N:18]([C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH2:17][CH2:16]3)[C:6]=2[CH3:26])[CH2:3][CH2:2]1.S(=O)(=O)(O)O.C(=O)([O-])[O-].[K+].[K+]>C(OC(=O)C)(=O)C>[CH:1]1([N:4]2[C:5]3[C:10](=[CH:9][C:8]([F:14])=[C:7]([N:15]4[CH2:16][CH2:17][N:18]([C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH2:19][CH2:20]4)[C:6]=3[CH3:26])[C:34](=[O:35])[C:28]([C:29]([O:31][CH2:32][CH3:33])=[O:30])=[CH:27]2)[CH2:2][CH2:3]1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 11430Potassium CarbonateHCID 15631832diethyl [N-cyclopropyl-N-[3-(4-ethoxycarbonyl-1-piperazinyl)-2-methyl-4-fluoro-6-nitrophenyl]aminomethylene]malonate

Product 1

HCID 15631833Ethyl 1-cyclopropyl-7-(4-ethoxycarbonyl-1-piperazinyl)-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylateYield 22.9%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

To a solution of diethyl [N-cyclopropyl-N-[3-(4-ethoxycarbonyl-1-piperazinyl)-2-methyl-4-fluoro-6-nitrophenyl]aminomethylene]malonate (1.0 g) in acetic anhydride (5 ml) is added conc. sulfuric acid (2 ml) with keeping at 50°-70° C. After stirring for 30 minutes, the reaction mixture is poured into ice water, and neutralized with potassium carbonate. The mixture is extracted with ethyl acetate, and the solvent is distilled off, and the resulting residue is purified by silica gel column chromatography (solvent, dichloromethane:methanol=10:1) and then recrystallized from ethyl acetate to give ethyl 1-cyclopropyl-7-(4-ethoxycarbonyl-1-piperazinyl)-6-fluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (0.19 g), as colorless prisms, m.p. 200°-202° C.

Workup

  1. customwith keeping at 50°-70° C
  2. extractionThe mixture is extracted with ethyl acetate
  3. distillationthe solvent is distilled off
  4. customthe resulting residue is purified by silica gel column chromatography (solvent, dichloromethane:methanol=10:1)
  5. customrecrystallized from ethyl acetate

Sources & evidence

ORD record
ord-105ae7f76f994151aabed3fec1e066e5
Source dataset
uspto-grants-1989_11
Patent number
US04880806

Reaction notes

Loading…