8-Chloro-3-ethoxycarbonyl-7-fluoro-1-methyl-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine → 8-Chloro-7-fluoro-1-methyl-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylic acid
Reaction equation
[Cl:1][C:2]1[C:3]([F:23])=[CH:4][C:5]2[C:6]([CH:22]=1)=[N:7][C:8]1[N:9]([CH3:21])[CH:10]=[C:11]([C:16]([O:18]CC)=[O:17])[C:12](=[O:15])[C:13]=1[CH:14]=2>C(O)(=O)C.Cl>[Cl:1][C:2]1[C:3]([F:23])=[CH:4][C:5]2[C:6]([CH:22]=1)=[N:7][C:8]1[N:9]([CH3:21])[CH:10]=[C:11]([C:16]([OH:18])=[O:17])[C:12](=[O:15])[C:13]=1[CH:14]=2Participants
4
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Procedure
A suspension of 15 g of 8-chloro-3-ethoxycarbonyl-7-fluoro-1-methyl-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine in 150 cm3 of acetic acid and 150 cm3 of hydrochloric acid as a 17.5% aqueous solution is heated at a temperature close to 100° C., with stirring, for 4 hours. After cooling to a temperature close to 20° C., the product is drained and washed with twice 150 cm3 of ethanol and then twice 100 cm3 of diethyl ether. 12.7 g of 8-chloro-7-fluoro-1-methyl-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine-3-carboxylic acid are obtained in the form of a beige solid which sublimes at 400°-405° C. and is used for the subsequent steps without further purification.
Workup
- temperatureis heated at a temperature
- customclose to 100° C.
- temperatureAfter cooling to a temperature
- customclose to 20° C.
- washwashed with twice 150 cm3 of ethanol
Sources & evidence
- ORD record
- ord-6fb10439c42a4502b5ef3333865ac8f5
- Source dataset
- uspto-grants-1991_04
- Patent number
- US05004745
Reaction notes
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