- Method adopting clean process for preparing H-acid
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The invention discloses a method adopting a clean process for preparing H-acid. The method comprises the following process: step (10), carrying out extraction treatment on denitrated matter to obtain dilute sulphuric acid and an extracted mixture, and carrying out re-extraction on the extracted mixture to obtain a nitro-T-acid solution; step (20), carrying out reduction treatment on the nitro-T-acid solution obtained in the step (10) to obtain an amino-T-acid solution; step (30), respectively carrying out concentration treatment on the amino-T-acid solution obtained in the step (20) and caustic soda liquid to obtain concentrated amino-T-acid solution and caustic soda liquid; step (40), carrying out alkali fusion treatment on the concentrated amino-T-acid solution and caustic soda liquid obtained in the step (30), and performing attenuation treatment to obtain attenuated alkali fusion matter; step (50), carrying out separation and filtration treatment on the attenuated alkali fusion matter obtained in the step (40) to obtain the H-acid. The preparation method disclosed by the invention adopts the clean process for preparing the H-acid, the production efficiency is high, the materials are saved, and the economic cost is reduced.
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Paragraph 0058; 0059; 0060; 0061; 0062
(2016/10/10)
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- Device for preparing H-acid
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The invention discloses a device for preparing H-acid, comprising a sulfonating device, a nitrating device, a denitration device, an extraction device, a reduction device, a concentration device, a dilution device, a separation and filter device and a drying device. An outlet of the sulfonating device is connected with an inlet of the nitrating device, an outlet of the nitrating device is connected with an inlet of the denitration device, an outlet of the denitration device is connected with an inlet of the extraction device, a first outlet of the extraction device is connected with an inlet of the reduction device, an outlet of the reduction device is connected with an inlet of the concentration device, an outlet of the concentration device is connected with an inlet of the dilution device, an outlet of the dilution device is connected with a first inlet of the separation and filter device, an outlet of the separation and filter device is connected with an inlet of the drying device, and a second outlet of the extraction device is connected with a second inlet of the separation and filter device. The device for preparing H-acid produces H-acid with a continuous production method, has the high production efficiency, saves materials and reduces economic cost.
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Paragraph 0025; 0026
(2016/10/27)
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- Method for preparing energy-efficient H-acid
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The invention discloses a method for preparing energy-efficient H-acid. The method comprises the steps of conducting sulfonation on liquid naphthalene to obtain a sulfonated substance, conducting nitration on the sulfonated substance to obtain a nitrated substance, conducting denitration on the nitrated substance to obtain a denitrated substance, conducting extraction on the denitrated substance to obtain dilute sulphuric acid and an extraction mixture, conducting reextraction on the extraction mixture to obtain nitro T-acid solution, conducting reduction on the nitro T-acid solution to obtain amino T-acid solution, conducting concentration on the amino T-acid solution and caustic soda liquid to obtain concentrated amino T-acid solution and caustic soda, conducting alkali fusion and dilution on the concentrated amino T-acid solution and caustic soda to obtain a diluted alkali fusion substance, conducting separation and filtration on the diluted alkali fusion substance to obtain H-acid filter cakes, and conducting drying on the H-acid filter cakes to obtain H-acid. By the adoption of the method, continuous production of H-acid can be achieved, and economic cost is low.
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Paragraph 0042; 0043; 0044; 0045; 0046
(2016/10/08)
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- Synthesis, characterization and RP-HPLC method development and validation for simultaneous determination of Koch acid and H acid
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1-amino-8-naphthol-3,6-disulfonic acid (H acid) is an important intermediate used for the synthesizing some dyestuffs and pharmaceuticals. The synthesis of H acid was followed by sulfonation, nitration, reduction and alkali fusion. The total yield was increased to 35% with 99% purity. This study focuses on cheap synthesis of H acid on an industrial scale. The composition and percentage of these compounds were characterized by making reactive dyes and chromatographic analysis, i.e. UV/Visible, IR and HPLC. The RP-HPLC method was developed; in the analysis of Koch acid (1-amino-naphthalene-3,6,8-trisulfonic acid) and H acid. The single HPLC method is useful, both, in the chemical intermediate (Koch acid) and for the final product (H acid).
- Bokhari, Syed Ahmad Raza,Khan, Rana Rashad Mahmood,Tahir, Muhammad Saqlain,Tahir, Naveed,Syed, Quratulain,Adnan, Ahmad
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p. 469 - 478
(2016/08/31)
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- The positional reactivity order in the sulfur trioxide sulfonation of benzene and naphtalene derivatives containing an electron-withdrawing substituent
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The reaction of sulfur trioxide with derivatives of benzene and naphthalene containing an electron-withdrawing substituent, viz.-SO3H, -SO2Ph, -NO2, -CHO, -COPh, -CO2H, and -CO2Me, in dichloromethane as solvent at ca. 22 deg C has been studied by analysis of the resulting mixtures of the sulfo derivatives with 1H-NMR.The initial sulfonation of the benzene derivatives yields the corresponding 3-sulfonic acid (3-S) and subsequently, with the exception of nitrobenzene and methyl benzoate, small amounts of 3,5-S2.Benzenesulfonic acid in addition undergoes sulfonylation giving 3,3'-di- and 3,5,3'-trisulfodiphenyl sulfone.Monosulfonation of naphtalene-1-S yields the 1,5-S2, 1,6-S2 and 1,7-S2 derivatives in a ratio of 71:20:9.On using a large excess of SO3, the eventual products are 1,3,5-S3, 1,3,6-S3 and 1,3,5,7-S4.Monosulfonation of naphthalene yields 5-S, 6-S, 7-S and 8-S in a 55:9:6:30 ratio, that of 1-benzoylnaphthalene 5-S, 6-S and 7-S in a ratio of 83:11:6, and 1-nitronaphtalene only the 5-S.The absence of peri sulfonation with 1-sulfo-, 1-benzoyl- and 1-nitronaphthalene is due to prohibitive steric hidrance. 1-Naphthoic acid and its methyl ester upon SO3 sulfonation and aqueous work-up both yield 5- and 8-sulfonaphthoic acid in a ratio of 65:35 and 77:21, respectively.The initially formed peri-substituted product is the intramolecular anhydride of 8-sulfo-1-naphthoic acid (5).All the 2-substituted naphthalenes yield 5-S and 8-S upon SO3 sulfonation of which the former sulfo isomer is far in excess.The positional reactivity orders for the SO3 sulfonation of the monosubstituted naphthalene derivatives are discussed in terms of the difference in reactivity of the α- and β-positions, and the steric and electronic effects of the deactivating substituent.
- Cerfontain, Hans,Zou, Yousi,Bakker, Bert H.
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p. 403 - 410
(2007/10/02)
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- On the positional reactivity order in the sulfuric acid sulfonation of the two naphthalenesulfonic acids
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The sulfonation in 98.5percent H2SO4 at 25.0 deg C of naphthalene-1-sulfonic acid yields 58percent 1,5-, 32percent 1,6-, and 10percent 1,7-disulfonic acids and that of the 2-sulfonic acid 4percent 1,3-, 74percent 1,6-, 18percent 1,7-, and 4percent 2,6- + 2,7-disulfonic acids.Further sulfonation of the latter disulfonic acid mixture in 105.2percent H2SO4 at 25.0 deg C yields 78percent 1,3,6- and 12percent 1,3,5- + 1,3,7-trisulfonic acids.Reaction of naphthalene-1,5-disulfonic acid with 105.2percent H2SO4 at 25 deg C yields 5-sulfonaphthalene-1-sulfonic anhydride.Partial rate factors for the sulfonation of naphthalene-1- and -2-sulfonate in highly concentrated aqueous sulfuric acid (where the sulfonating entity is H2S2O7) are reported.They are discussed in terms of the difference in the reactivity of the α- and β-positions of the naphthalene skeleton and the electronic and steric effects of the sulfonate substituent already present.
- Wit, Peter De,Cerfontain, Hans
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p. 1453 - 1455
(2007/10/02)
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- Process for the preparation of naphthalene-1,3,6-trisulphonic acid
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A process has been invented for the preparation of naphthalene-1,3,6-trisulphonic acid by sulphonating naphthalene with sulphuric acid and oleum, characterized in that naphthalene and most of the oleum are simultaneously metered into sulphuric acid or oleum of low concentration, which has been initially introduced, at about 140° to 240° C., the temperature is kept at about 140° to 240° C. for some time, the remainder of the oleum is then added at about 140° to 240° C. and the mixture is then further stirred for some time. Naphthalene-1,3,6-trisulphonic acid is a known important intermediate used, for example, in the preparation of T-acid, H-acid and chromotropic acid.
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