88-72-2 Usage
Overview
O-nitrotoluene is also known as 2-nitrotoluene or 1-methyl-2-nitrobenzene,and is yellow oily transparent liquid. It has the smell of nitrobenzene. The relative density is 1.1629. The melting point is-2.9℃ (α-type, stable type),-9.5℃ (β-type, non-stable type). The boiling point is 221.7 °C, 118 °C (2.133×103Pa) and 50.0 °C (0.133×103Pa). The flash point is 106.1 °C (closed system). The refractive index is 1.5450. The viscosity is 0.0262 mPa?s (15℃). The vapor pressure (×103 Pa) is 10.906 (5℃), 12.639 (10℃), 14.612 (20℃), 15.892 (30℃). It is slightly soluble in water (0.061 at 30°C), soluble in benzene, chloroform and petroleum ether and immiscible with ethanol and ether. It can evaporate together with water vapor. Due to the strong electron-withdrawing ability of nitro group, the methyl of is easy to be oxidized to form o-nitrobenzaldehyde or o-nitrobenzoic acid according to oxidation conditions. And o-nitrotoluene can be reduced in the presence of catalyst to generate o-toluidine, which can generate 2,4 or 2,6 dinitrotoluene after further nitration. O-nitrotoluene can also be chlorinated to generate nitrobenzyl chloride. In addition, o-nitrotoluene can also generate azo compounds. LD50 (rat oral) is 801mg/kg.
O-nitrotoluene is mainly used as the raw material of dyestuffs to prepare 4-chloro-2-nitrotoluene, 6-chloro-2-nitrotoluene, o-toluidine, o-tolidine, 2,6-dichlorobenzaldehyde and other dyestuffs intermediates, in which 4-chloro-2-nitrotoluene is a pharmaceutical raw material and o-toluidine is the raw material of pesticide fungicides and spices. O-nitrotoluene is a pharmaceutical raw material to prepare 2,2'-dinitrobenzene, o-nitrobenzyl bromide, bromine alkane and other medicines, and is also the raw material to prepare indole to be used as amino acids and plant growth regulators. O-nitrotoluene is the raw material to prepare dinitrotoluene to be used as powder. O-toluidine can also be used as vulcanization accelerator and to prepare o-nitrobenzoic acid as pharmaceutical raw material.
Chemical Properties
Different sources of media describe the Chemical Properties of 88-72-2 differently. You can refer to the following data:
1. Yellow flammable liquid; insoluble in water; soluble in chloroform and benzene; immiscible with ethanol and ethyl ether.
2. light yellow to darker yellow-green liquid
Application
Used for the intermediates of dyes and pesticides, and also for the production of coatings, plastics and pharmaceuticals. O-nitrotoluene is mainly used in the production of o-toluidine, o-tolidine, and also used as the important raw materials of dyes, paints, plastics and pharmaceutical. In the pharmaceutical industry, it is used for the production of nifedipine, tegretol, imipramine hydrochloride, bromide has hydrochloride amine and sodium dicloxaeillin.I can also be used for dyes, pharmaceuticals, pesticides, plastics and other industries.
Production method
Nitrify toluene with mixed acid to generate mixed nitrotoluene, which mainly consists of o-nitrotoluene (about two-thirds) and p-nitrotoluene (about one-third). The mixed nitrotoluene can be separated to get the pure product. Add toluene to the reactor and cool to below 25℃. Then add the mixed acid (ie, 25-30% of nitric acid, 55-58% of sulfuric acid and 20-21% of water) and control the temperature not exceeding 50℃. Stir for 1-2h, and then stand for 6h. Separate the generated nitrotoluene, and wash them with water and alkali liquor to remove unreacted toluene and aliphatic compound. The crude nitrotoluene products consist of 55-60% of o-nitrotoluene, 2-5% of m-nitrotoluene and 35-40% of p-nitrotoluene, with a yield of 90-95%. The various isomers can be separated by crude distillation and crystallization according to the difference of the boiling point and melting point. Namely, first distill the crude nitrotoluene under vacuum to separate out the majority of o-nitrotoluene. And then the residual fraction containing more p-nitrotoluene is separated by vacuum distillation, and cooled for crystallization and separated to obtain the finished products. The tarry substance with high boiling point remains in the still. M-nitrotoluene remains in the mother liquor separated out the p-nitrotoluene, and can be obtained by rectification after repeated accumulation. The purity of ortho and para nitrotoluene can respectively reach 98% and 99%. The domestic process is the two-pot series process, and the reaction temperature of the main pot is 40-45℃ and the second pot is 50-55℃. The preparation of mixed acid is roughly similar, including 26-28% of nitric acid, 56-57% of sulfuric acid and 16-18% of water. The raw material consumption quota: toluene (98%) 800kg/t, nitric acid (98%) 470kg/t, sulfuric acid (92.5%) 450kg/t, caustic soda (42%) 100kg /t
Description
o-Nitrotoluene is a yellow-coloured liquid. It is used for the synthesis of a variety of industrial
products. These include to synthesise agricultural and rubber chemicals, azo and sulphur
dyes, and dyes for cotton, wool, silk, leather, and paper. O-nitrotoluene decomposes
on contact with strong oxidants, reducing agents, acids, or bases producing toxic fumes,
nitrogen oxides, and carbon monoxide.
Physical properties
Clear, colorless to pale yellowish combustible liquid with a faint, aromatic odor. May darken on
exposure to air.
Uses
Different sources of media describe the Uses of 88-72-2 differently. You can refer to the following data:
1. 2-Nitrotoluene is a nitroaromatic compound. It is used in the synthesis of intermediates for azo dyes, sulfur dyes, rubber chemicals, and agriculture chemicals; typical intermediates are o-toluidine, o-nitrobenzaldehyde, 2-nitro-4-chlorotoluene, 2-nitro-6-chlorotoluene, 2-amino-4-chlorotoluene (Fast Scarlet TR Base), and 2-amino-6-chlorotoluene (Fast Red KB Base).
2. 2-Nitrotoluene is used as an intermediate for the o-toludine synthesis, which finds application in the dyestuff industry. It is employed as a reagent in detecting and photometric determining oxidizing agent. It is also used in the determination of prussic acid content in the air. It acts as a precursor to prepare 2-amino-4-chlorotoluene, 2-amino-6-chlorotoluene, nitrotoluenesulfonic acids and toluene nitrosulfonic chlorides. It acts as a nitrogen supplement in the culture medium of pseudomonas sp. strain ClS1. It acts as a carbon and energy supplement in the culture medium of Pseudomonas sp. strain JS42.
Preparation
2-Nitrotoluene was synthesized by nitration of toluene with mixed acid, A mixture of mononitrotoluene isomers can be prepared from the nitration of toluene between -10 oC and 30 oC. Lower temperatures result in little or no reaction, while higher temperatures will result in double nitration forming dinitrotoluenes.
Definition
ChEBI: 2-nitrotoluene is a mononitrotoluene that is toluene carrying a nitro substituent at position 2. It has a role as an environmental contaminant and a carcinogenic agent.
General Description
Light yellow oily liquid with a characteristic odor of aromatic nitro compounds. Sinks in water. Derived from toluene by nitration and separation by fractional distillation. Flash point 223°F.
Air & Water Reactions
Insoluble in water.
Reactivity Profile
2-Nitrotoluene is toxic by inhalation, ingestion and skin aborption, targeting the blood, central nervous system, skin, and gastrointestinal tract. Symptoms include, anoxia, weakness or dizziness, nausea and vomiting. If 2-Nitrotoluene contacts the eye, the eye should be irrigated immediately. If 2-Nitrotoluene contacts the skin, the area should be washed with soap. If inhaled, respiratory support should be administered. Finally, if ingested, medical attention should be sought. 2-Nitrotoluene also reacts with sulfuric acid, sodium hydroxide, hydrogen, sodium, tetranitromethane, reducing agents and strong oxidizers. 2-Nitrotoluene is very heat sensitive.
Hazard
Toxic by inhalation, ingestion, skin absorption. Methemoglobinemia. Probable carcinogen.
Health Hazard
INHALATION, INGESTION, OR SKIN: Headache, flushing of face, dizziness, dyspnea (difficult breathing), cyanosis, nausea, vomiting, muscular weakness, increased pulse and respiratory rate, irritability, and convulsions. SKIN: Irritation.
Safety Profile
Confirmed carcinogen.
A poison. Moderately toxic by ingestion.
Mucous membrane effects by inhalation.
Mutation data reported. Combustible when
exposed to heat or open flame. To fight fire,
use water spray, fog, foam, CO2. Potentially
explosive reaction with alkali (e.g., sodmm
hydroxide). When heated to decomposition
it emits toxic fumes of NOx. See also other
methylnitrobenzene entries and NITRO
COMPOUNDS OF AROMATIC
HYDROCARBONS.
Carcinogenicity
o-Nitrotoluene is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals and supporting data on mechanisms of carcinogenesis.
Environmental fate
Biological. Robertson et al. (1992) reported that toluene dioxygenases from Pseudomonas
putida F1 and Pseudomonas sp. Strain JS 150 oxidized the methyl group forming 2-nitrobenzyl
alcohol.
Purification Methods
Crystallise 2-nitrotoluene (repeatedly) from absolute EtOH by cooling in a Dry-ice/alcohol mixture. Further purify it by passing an alcoholic solution through a column of alumina. [Beilstein 5 IV 845.]
Check Digit Verification of cas no
The CAS Registry Mumber 88-72-2 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 8 and 8 respectively; the second part has 2 digits, 7 and 2 respectively.
Calculate Digit Verification of CAS Registry Number 88-72:
(4*8)+(3*8)+(2*7)+(1*2)=72
72 % 10 = 2
So 88-72-2 is a valid CAS Registry Number.
88-72-2Relevant articles and documents
Aromatic nitration with nitric acid/trifluoromethanesulfonic anhydride
Olah,Reddy,Prakash
, p. 1087 - 1089 (1992)
Nitric acid/trifluoromethanesulfonic (triflic) anhydride was shown to be a highly effective electrophilic nitrating agent. A series of aromatics were nitrated under mild conditions in high yields. Similar results were also obtained when using nitric acid/
Nitrobenzyl Derivatives as Bioreductive Alkylating Agents: Evidence for the Reductive Formation of a Reactive Intermediate
Kirkpatrick, D. L.,Johnson, K. E.,Sartorelli, A. C.
, p. 2048 - 2052 (1986)
o- and p-nitrobenzyl chlorides and carbamates were chemically and electrochemically reduced in the presence and absence of the nucleophile morpholine; activation of these compounds by reduction was required to produce an intermediate capable of alkylation.The reduction products formed by the catalytic hydrogenation of each compound were examined by gas chromatography-mass spectrometry.In addition, the products generated by controlled-potential electrolysis were examined by ESR and NMR spectrometry.After a one-electron reduction, o- and p-nitrobenzyl chlorides were activated to the nitrobenzyl radicals, which subsequently dimerized to the dinitrobibenzyl derivatives or reacted with morpholine when present in the reaction medium to form the (nitrobenzyl)morpholine adducts.The nitrobenzyl carbamates were not activated after a one-electron reduction; however, the morpholine and the ether adducts of these agents were observed after catalytic hydrogenation.It was assumed that an intermediate or intermediates formed after the one-electron reduction product, or the full reduction product of the carbamates, were capable of alkylating various nucleophiles.Chemical reduction of the potential bioreductive alkylating agent (o-nitrobenzyl)-6-thioguanine produced (o-aminobenzyl)-6-thioguanine, indicating a lack of formation of a reactive electrophile by reduction. (o-, (m-, and (p-nitrobenzyl)-6-thioguanine analogues were also examined for cytotoxic activity toward EMT6 tumor cells under aerobic and hypoxic conditions.In agreement with the inability of (o-nitrobenzyl)-6-thioguanine to form a reactive species after chemical reduction, no decrease in the survival of neoplastic cells exposed to 10-4 M drug occurred under either aerobic or hypoxic conditions.
Application of H-ZSM-5 Zeolite for Regioselective Mononitration of Toluene
Kwok, Thomas J.,Jayasuriya, Keerthi,Damavarapu, Reddy,Brodman, Bruce W.
, p. 4939 - 4942 (1994)
The nitration of toluene with n-propyl nitrate has been carried out in the presence of H-ZSM-5 as the catalyst.Several H-ZSM-5 catalysts with different Si/Al ratios were investigated to determine the influence of varying Si/Al ratios on the catalytic activity.It was found that high Si/Al ratios enhanced the regioselectivity for the p-nitrotoluene over the ortho isomer under comparable conditions.The best o:m:p product distribution (5:0:95) was achieved using H-ZSM-5 with a Si/Al ratio of 1000.The isolable yield is 54percent.In contrast to conventional nitration methods, the product distribution reported in this study is remarkable.
Some Aspects of Nitration of Aromatics by Lower Oxidation States of Nitrogen
Milligan, Barton
, p. 1495 - 1500 (1983)
Nitration of benzene and toluene in trifluoroacetic acid (TFA) solution with sodium nitrite (N(III)) and nitrogen dioxide (N(IV)) occurs relatively slowly to produce mononitroarenes and oxidized byproducts.The yield of nitroarene improves as the ratio of
Aromatic Substitution. 50. Mercury(II)-Promoted Azeotropic Nitration of Aromatics over Nafion-H Solid Superacidic Catalyst
Olah, George A.,Krishnamurthy, V. V.,Narang, Subhash C.
, p. 596 - 598 (1982)
-
Regioselective catalyzed nitration of toluene by zeolites
Dong, Xiongzi,Peng, Xinhua
, p. 2341 - 2342 (2015)
The nitration of toluene with nitric acid and nitrogen dioxide as nitration agent was studied. The effect of zeolite catalysts was also discussed. By using zeolite as catalysis, the yield of nitro-toluene was improved with nitric acid as nitration agent. The conversion of toluene and yield of nitro-toluene were both greatly enhanced with nitrogen dioxide as nitration agent.
Nitration of aromatics with dinitrogen pentoxide in a liquefied 1,1,1,2-tetrafluoroethane medium
Fauziev, Ruslan V.,Kharchenko, Alexandr K.,Kuchurov, Ilya V.,Zharkov, Mikhail N.,Zlotin, Sergei G.
, p. 25841 - 25847 (2021/08/09)
Regardless of the sustainable development path, today, there are highly demanded chemical productions still operating that bear environmental and technological risks inherited from the previous century. The fabrication of nitro compounds, and nitroarenes in particular, is traditionally associated with acidic wastes formed in nitration reactions exploiting mixed acids. However, nitroarenes are indispensable for industrial and military applications. We faced the challenge and developed a greener, safer, and yet effective method for the production of nitroaromatics. The proposed approach comprises the application of an eco-friendly nitrating agent, namely dinitrogen pentoxide (DNP), in the medium of liquefied 1,1,1,2-tetrafluoroethane (TFE) - one of the most non-hazardous Freons. Importantly, the used TFE is not emitted into the atmosphere but is effortlessly recondensed and returned into the process. DNP is obtainedviathe oxidation of dinitrogen tetroxide with ozone. The elaborated method is characterized by high yields of the targeted nitro arenes, mild reaction conditions, and minimal amount of easy-to-utilize wastes.
Selective Mild Oxidation of Anilines into Nitroarenes by Catalytic Activation of Mesoporous Frameworks Linked with Gold-Loaded Mn3O4 Nanoparticles
Armatas, Gerasimos S.,Daikopoulou, Vassiliki,Koutsouroubi, Eirini D.,Lykakis, Ioannis N.,Skliri, Euaggelia
, (2021/11/01)
This work reports the synthesis and catalytic application of mesoporous Au-loaded Mn3O4 nanoparticle assemblies (MNAs) with different Au contents, i. e., 0.2, 0.5 and 1 wt %, towards the selective oxidation of anilines into the corresponding nitroarenes. Among common oxidants, as well as several supported gold nanoparticle platforms, Au/Mn3O4 MNAs containing 0.5 wt % Au with an average particle size of 3–4 nm show the best catalytic performance in the presence of tert-butyl hydroperoxide (TBHP) as a mild oxidant. In all cases, the corresponding nitroarenes were isolated in high to excellent yields (85–97 %) and selectivity (>98 %) from acetonitrile or greener solvents, such as ethyl acetate, after simple flash chromatography purification. The 0.5 % Au/Mn3O4 catalyst can be isolated and reused four times without a significant loss of its activity and can be applied successfully to a lab-scale reaction of p-toluidine (1 mmol) leading to the p-nitrotulene in 83 % yield. The presence of AuNPs on the Mn3O4 surface enhances the catalytic activity for the formation of the desired nitroarene. A reasonable mechanism was proposed including the plausible formation of two intermediates, the corresponding N-aryl hydroxylamine and the nitrosoarene.
NITRATION
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Page/Page column 36; 41; 46; 64; 37; 47; 42; 65, (2020/05/28)
The present invention relates to a process for preparing a nitrated compound, comprising the step of reacting a compound (A) comprising at least one substituted or unsubstituted aromatic or heteroaromatic ring, wherein said heteroaromatic ring comprises at least one heteroatom selected from the group consisting of oxygen, sulfur, phosphor, selenium and nitrogen, with a compound of formula (I) wherein Y is selected from the group consisting of hydrogen and nitro.