Sulfuric Acid → 4-Fluoro-2-methoxy-5-nitroaniline
Reaction equation
[F:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[C:4]([O:9][CH3:10])[CH:3]=1.OS(O)(=O)=O.[N+:16]([O-])([O-:18])=[O:17].[K+].[NH4+].[OH-]>>[F:1][C:2]1[C:8]([N+:16]([O-:18])=[O:17])=[CH:7][C:5]([NH2:6])=[C:4]([O:9][CH3:10])[CH:3]=1Participants
Procedure
4-Fluoro-2-methoxyaniline (2.4 g, 17.00 mmol) was added portionwise to concentrated H2SO4 (15 mL) which was cooled in a ice/water bath, and where the temperature was kept below 15° C. during the addition. The mixture was stirred until all the solid that formed had dissolved. KNO3 (0.815 mL, 17.00 mmol) was added portionwise such that the temperature was maintained below 10° C. The mixture was stirred overnight and then poured onto ice/water. The mixture was basified with concentrated NH4OH. The resulting solid was filtered off and then dissolved in CH2Cl2, washed with water, dried (Na2SO4) and concentrated onto silica. Purification by FCC, eluting with 50-0% heptane in CH2Cl2 gave the title compound (2.450 g, 77%) as a yellow crystalline solid; 1H NMR: 3.91 (3H, s), 5.21 (2H, s), 7.03 (1H, d), 7.35 (1H, d); m/z: ES+ MH+ 187.4.
Workup
- temperaturewas cooled in a ice/water bath
- additionwhere the temperature was kept below 15° C. during the addition
- customthat formed
- dissolutionhad dissolved
- temperaturewas maintained below 10° C
- stirringThe mixture was stirred overnight
- additionpoured onto ice/water
- filtrationThe resulting solid was filtered off
- dissolutiondissolved in CH2Cl2
- washwashed with water
- dry with materialdried (Na2SO4)
- concentrationconcentrated onto silica
- customPurification by FCC
- washeluting with 50-0% heptane in CH2Cl2
Sources & evidence
- ORD record
- ord-e5f5a8e89f9c496787ab527ac1a5a7af
- Source dataset
- uspto-grants-2015_02
- Patent number
- US08946235B2
Reaction notes
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