Sulfuric Acid → 5-Fluoro-2-nitrophenol
Reaction equation
F[C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[N+:9]([O-:11])=[O:10].[OH-].[K+].S(=O)(=O)(O)[OH:15].[OH-].[Ca+2].[OH-]>O>[N+:9]([C:3]1[CH:4]=[CH:5][C:6]([F:8])=[CH:7][C:2]=1[OH:15])([O-:11])=[O:10]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 55 °C
Procedure
159.1 g (1 mol) of 2,4-difluoronitrobenzene and 550 g of water are initially introduced and are heated to 55° C. With vigorous stirring, 241.2 g (2.15 mol) of 50% strength potassium hydroxide solution are added dropwise over 4 hours and the temperature is maintained at 55° C. (exothermic reaction). Stirring is then continued for another 2 hours at this temperature. The pH is then adjusted to 4.3 (25° C.) using 88 g of sulfuric acid, and 74.1 g of calcium hydroxide are added. The pH is readjusted to 5.0 and the introduction of steam is started. During distillation the pH is decreased from 5 to 1.5 by dropwise addition of sulfuric acid. The product is isolated by cooling and filtering the distillate. After drying, 117.9 g (0.750 mol, 75% of theory) of bright yellow 2-nitro-5-fluorophenol is obtained, which is more than 99.9% pure according to GC and HPLC (solidification point 32.1° C.).
Workup
- temperaturethe temperature is maintained at 55° C.
- custom(exothermic reaction)
- customis then adjusted to 4.3 (25° C.)
- additionare added
- distillationDuring distillation the pH
- additionis decreased from 5 to 1.5 by dropwise addition of sulfuric acid
- customThe product is isolated
- temperatureby cooling
- filtrationfiltering the distillate
- customAfter drying
Sources & evidence
- ORD record
- ord-68297f5d318043ef80cec7e0866d9bb0
- Source dataset
- uspto-grants-1993_07
- Patent number
- US05227535
Reaction notes
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