Process for the preparation of 2-nitro-3, 6-dichlorophenol
AssigneeHoechst Aktiengesellschaft
InventorsMichael Meier, Heinz-Georg Kautz
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Abstract
2-Nitro-3,6-dichlorophenol is prepared by sulfonation of 2,5-dichlorophenol and subsequent nitration and desulfonation, in which the nitration is carried out by metering in a nitrating acid composed of 98 to 100% strength nitric acid and 96 to 100% strength sulfuric acid at temperatures from -15.degree. to 35.degree. C. and a metering time of at least 1 hour.
Claims20
A process for the preparation of 2-nitro-3,6-dichlorophenol by sulfonation of 2,5-dichlorophenol and subsequent nitration and desulfonation, which comprises carrying out the nitration by metering in a nitrating acid comprising 98 to 100% strength nitric acid and 96 to 100% strength sulfuric acid at temperatures from -15.degree. to 35.degree. C. and for a metering time of at least 1 hour.
A process for the preparation of 2-nitro-3,6-dichlorophenol from 2,5-dichlorophenol, comprising:
- a. sulfonating the 2,5-dichlorophenol,
- b. nitrating the resulting sulfonated product by metering in a nitrating acid comprising 98 to 100% strength nitric acid and 96 to 100% strength sulfuric acid at a temperature in the range of -15.degree. to 35.degree. C. and for a metering time of at least one hour, and
- c. desulfonating the resulting nitrated product, and recovering 2-nitro-3,6-dichlorophenol.
A process for the preparation of 2-nitro-3,6-dichlorophenol by sulfonation of 2,5-dichlorophenol and subsequent nitration and desulfonation, which comprises carrying out the nitration by metering in a nitrating acid compose of 90 to 100% strength nitric acid and 96 to 100% strength sulfuric acid at temperature from -15.degree. to 35.degree. C. and metering time of at least 1 hour, and wherein said desulfonation is carried out using 98 to 100% strength sulfuric acid, with said amount of sulfuric acid employed being from 2.5 to 12 times the amount of weight relative to 2,5-dichlorophenol and said sulfonation is carried out at 70.degree. to 130.degree. C.
Dependencies are inferred from the claim text.