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P-phenylenediamine Production Process
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Laure M. Brussolo
P-phenylenediamine Production Process
React benzene with chlorine in the presence of $\ce{FeCl3}$ to yield chlorobenzene.
According to Ullmann's Encyclopedia of Industrial Chemistry:
Most monochlorobenzene is now produced from benzene and chlorine in continuously operated plants. Depending on the ratio of benzene to chlorine chosen, one can achieve either a low rate of benzene conversion and little dichlorobenzene
formation, or almost complete conversion of the benzene with a higher degree of dichlorobenzene formation. [...] The composition of a chlorination mixture containing the highest possible proportion of monochlorobenzene has been given as
4–5% unreacted benzene, 73% monochlorobenzene, and 22–23% dichlorobenzenes.
Nitrate chlorobenzene to obtain a mixture of 2-nitrochlorobenzene and 4-nitrochlorobenzene. Separate the isomers.
In Ullmann's Encyclopedia of Industrial Chemistry, we find:
Nitration of chlorobenzene with mixed acid (30/56/14) typically gives an isomer
mix in 98 % yield consisting of 34–36% 2-chloronitrobenzene, 63–65 % 4-chloronitrobenzene, and only ca. 1% 3-chloronitrobenzene.
"Mixed acid" refers to a mixture of nitric acid, sulfuric acid and water.
React 4-nitrochlorobenzene with ammonia (Nucleophilic aromatic substitution) to obtain 4-nitroaniline.
According to Ullmann's Encyclopedia of Industrial Chemistry, the reaction conditions as as follows:
4-Nitroaniline is produced in an agitated titanium reactor in 99.3 % yield by reacting 4-chloro nitrobenzene with a tenfold excess of aqueous ammonia at 175 °C and 4.2 MPa (42 bar) for 10 h.
Ullmann's Encyclopedia of Industrial Chemistry cites a patent by MONSANTO (DE1768518) as the relevant reference.
React benzene with chlorine in the presence of $\ce{FeCl3}$ to yield chlorobenzene.
According to Ullmann's Encyclopedia of Industrial Chemistry:
Most monochlorobenzene is now produced from benzene and chlorine in continuously operated plants. Depending on the ratio of benzene to chlorine chosen, one can achieve either a low rate of benzene conversion and little dichlorobenzeneformation, or almost complete conversion of the benzene with a higher degree of dichlorobenzene formation. [...] The composition of a chlorination mixture containing the highest possible proportion of monochlorobenzene has been given as4–5% unreacted benzene, 73% monochlorobenzene, and 22–23% dichlorobenzenes.
Nitrate chlorobenzene to obtain a mixture of 2-nitrochlorobenzene and 4-nitrochlorobenzene. Separate the isomers.
In Ullmann's Encyclopedia of Industrial Chemistry, we find:
Nitration of chlorobenzene with mixed acid (30/56/14) typically gives an isomermix in 98 % yield consisting of 34–36% 2-chloronitrobenzene, 63–65 % 4-chloronitrobenzene, and only ca. 1% 3-chloronitrobenzene.
"Mixed acid" refers to a mixture of nitric acid, sulfuric acid and water.
React 4-nitrochlorobenzene with ammonia (Nucleophilic aromatic substitution) to obtain 4-nitroaniline.
According to Ullmann's Encyclopedia of Industrial Chemistry, the reaction conditions as as follows:
4-Nitroaniline is produced in an agitated titanium reactor in 99.3 % yield by reacting 4-chloro nitrobenzene with a tenfold excess of aqueous ammonia at 175 °C and 4.2 MPa (42 bar) for 10 h.
Ullmann's Encyclopedia of Industrial Chemistry cites a patent by MONSANTO (DE1768518) as the relevant reference.
Mr. Klaus Warzecha, (i).Your answer describes synthesis of para phenylenediamine(PPD) by Reduction of Para Nitroaniline(PNA) with iron. (ii). Thus obtained PPD contains lots of iron impuries with other isomers, and therefore cannot be used as raw material(Monomer)for production of Para amide fiber(Kevlar). (iii). For this purpose catalytic Hydrogenation of PNA is carried out to produce PPD of desired quality(Grade). This is my simple understanding. I am open for edition/addition, please come back.More
According to Ullmann's Encyclopedia of Industrial Chemistry:
In Ullmann's Encyclopedia of Industrial Chemistry, we find:
"Mixed acid" refers to a mixture of nitric acid, sulfuric acid and water.
React 4-nitrochlorobenzene with ammonia (Nucleophilic aromatic substitution) to obtain 4-nitroaniline.
According to Ullmann's Encyclopedia of Industrial Chemistry, the reaction conditions as as follows:
Ullmann's Encyclopedia of Industrial Chemistry cites a patent by MONSANTO (DE1768518) as the relevant reference.
According to Ullmann's Encyclopedia of Industrial Chemistry:
In Ullmann's Encyclopedia of Industrial Chemistry, we find:
"Mixed acid" refers to a mixture of nitric acid, sulfuric acid and water.
React 4-nitrochlorobenzene with ammonia (Nucleophilic aromatic substitution) to obtain 4-nitroaniline.
According to Ullmann's Encyclopedia of Industrial Chemistry, the reaction conditions as as follows:
Ullmann's Encyclopedia of Industrial Chemistry cites a patent by MONSANTO (DE1768518) as the relevant reference.
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