4-Nitrotoluene → 2-Methyl-5-nitrobenzenesulfonic acid

HRID 1649949Notes

Reaction equation

HRID 1649949 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([CH3:10])=[CH:6][CH:5]=1)([O-:3])=[O:2].[OH:11][S:12](O)(=[O:14])=[O:13].O=S(=O)=O>O>[N+:1]([C:4]1[CH:9]=[C:8]([S:12]([OH:14])(=[O:13])=[O:11])[C:7]([CH3:10])=[CH:6][CH:5]=1)([O-:3])=[O:2]

Participants

4

Reactant 2

HCID 74734-Nitrotoluene2×HCID 24681Fuming sulfuric acid3×

Product 1

HCID 84582-Methyl-5-nitrobenzenesulfonic acidYield 99.15%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

After 2.8 hours of operation, the cascade reaction train was shut down, including 4-nitrotoluene, oleum, and water flows. The molten sulfonation mass in the first three reactors was allowed to solidify. Several days later, the reactors were heated to about 105°-115° C. The reactant feeds were restarted using oleum with an 82.7% free SO3 assay. The 4-nitrotoluene and oleum flows were set at 4.18 g/min and 3.4 g/min (SO3 excess 15%). The water flow to the fourth cascade vessel was started at 13.9 g/min. After operating the systems for five hours, samples were taken from the first three reactors and analyzed. The conversion in R-1, R-2 and R-3 were 97.0, 99.4, and 99.98 respectively. After 5.8 hours running, samples were again taken and analyzed. Conversion was 97.4% in the first reactor, 99.4% in the second and 100% in the third. The final sample collected at the overflow from the dilution vessel (#4 ) for 68 minutes showed 4-nitrotoluene conversion to be 99.7% with a yield of 99.15% of 4-nitrotoluene-2-sulfonic acid. 0.73% of theory yield was lost to sulfone formation. The final solution contained only 0.02% of unreacted 4-nitrotoluene and 16% sulfuric acid relative to 4-nitrotoluene-2-sulfonic acid. The dilute 30% 4-nitrotoluene-2-sulfonic acid solution is ready for use in other processes without any further treatment.

Workup

  1. customthe cascade reaction train
  2. temperatureSeveral days later, the reactors were heated to about 105°-115° C
  3. customfor five hours
  4. waitAfter 5.8 hours running
  5. customThe final sample collected at the overflow from the dilution vessel (#4 ) for 68 minutes

Sources & evidence

ORD record
ord-4ff19c4a46f24c368c42effbb0527854
Source dataset
uspto-grants-1990_05
Patent number
US04922008

Reaction notes

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