Sulfuric Acid → 4-(Methylamino)-3-nitrobenzoic acid
Reaction equation
Cl[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12].[CH3:14][NH2:15].S(=O)(=O)(O)O>>[CH3:14][NH:15][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12]Participants
Procedure
400 g (1.98 mol) of 4-chloro-3-nitrobenzoic acid were suspended in 1025 g of a 25-30% aqueous solution of methylamine. After heating to reflux temperature, an orange solution was obtained. The solution was kept at reflux temperature for 4 hours. The solution was cooled to room temperature, and pH was adjusted to about 2 by addition of 2M aqueous sulphuric acid. Precipitation of an orange solid was observed, which was isolated by filtration. The filtered cake was washed with 500 mL of water. The wet solid was mixed with 1.5 L of ethanol and heated to reflux temperature for 1 hour. After cooling to room temperature, the resulting suspension was filtered and the cake was dried at 60° C. under vacuum to obtain 371 g of 4-(methylamino)-3-nitrobenzoic acid as an orange powder. Yield: 95.5%. Purity (HPLC, method 2): 99.4%.
Workup
- temperatureAfter heating
- temperatureto reflux temperature
- customan orange solution was obtained
- temperatureat reflux temperature for 4 hours
- customPrecipitation of an orange solid
- customwhich was isolated by filtration
- washThe filtered cake was washed with 500 mL of water
- additionThe wet solid was mixed with 1.5 L of ethanol
- temperatureheated
- temperatureto reflux temperature for 1 hour
- temperatureAfter cooling to room temperature
- filtrationthe resulting suspension was filtered
- customthe cake was dried at 60° C. under vacuum
Sources & evidence
- ORD record
- ord-65c7db7d64a046c3a01a3c95e6522417
- Source dataset
- uspto-grants-2015_07
- Patent number
- US09086390B2
Reaction notes
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