Regioselective Nitration of m-Xylene Catalyzed by Zeolite Catalyst

2015 ◽  
Vol 68 (7) ◽  
pp. 1122 ◽  
Author(s):  
Xiongzi Dong ◽  
Xinhua Peng
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Zeolite Catalyst ◽  
Molecular Volume ◽  
Acetyl Nitrate ◽  
Regioselective Nitration ◽  
Excellent Selectivity

Nitration with nitric acid and acetic anhydride via acetyl nitrate as nitrating species is efficient with the substrate m-xylene as solvent. Zeolite Hβ with an SiO2/Al2O3 ratio of 500 was found to be the most active of the catalysts tried both in yield and regioselectivity in the nitration of m-xylene. The molecular volume of the reactants was calculated with the Gaussian 09 program at the B3LYP/6–311+G(2d, p) level and compared with the size of the zeolite Hβ channels. A range of other substrates were subjected to the nitrating system under the same conditions as those optimized for m-xylene and excellent selectivity was obtained.

Addition Reactions in the Nitration of Some Polycyclic Aromatic Compounds

1972 ◽  
Vol 50 (20) ◽  
pp. 3367-3372 ◽  
Author(s):  
A. Fischer ◽  
D. R. A. Leonard
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Nitro Group ◽  
Aromatic Compounds ◽  
Addition Reaction ◽  
Polycyclic Aromatic Compounds ◽  
Addition Reactions ◽  
Polycyclic Aromatic ◽  
Acetyl Nitrate

Reaction of 3-oxo-1,2,3,7,8,9,10,10a-octahydrocyclohepta[de]naphthalene with nitric acid in acetic anhydride gives two stereoisomeric 4-acetoxy-6a-nitro-3-oxo-1,2,3,4,6a,7,8,9,10,10a-decahydrocyclohepta[de]-naphthalenes as well as the expected nitro substitution products. Formation of these adducts from a substrate containing a meta-directing deactivating substituent shows that the 1,4-addition reaction of acetyl nitrate is more general than previously suspected. 1,4-Acetyl nitrate adducts are also formed from tetralin, benzsuberane, 5,6,7,8-tetrahydrocyclohepta[fg]acenaphthene, and 1,2,3,4,7,8,9,10-octahydrodicyclohepta[de,ij]naphthalene. Decomposition of the last two adducts gives in each case a product with the nitro group substituted into the alicyclic ring.

REACTIONS OF PHENYL-SUBSTITUTED HETEROCYCLIC COMPOUNDS: II. NITRATIONS AND BROMINATIONS OF 1-PHENYLPYRAZOLE DERIVATIVES

1963 ◽  
Vol 41 (6) ◽  
pp. 1540-1547 ◽  
Author(s):  
Misbahul Ain Khan ◽  
Brian M. Lynch ◽  
Yuk-Yung Hung
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Heterocyclic Compounds ◽  
Electrophilic Substitution ◽  
Chloroform Solution ◽  
Pyrazole Ring ◽  
Conjugate Acid ◽  
Acetyl Nitrate ◽  
Silver Sulphate ◽  
Mixed Acids

Nitrations of 1-phenylpyrazole (I), 1-p-biphenylylpyrazole (II), and 1,5-diphenylpyrazole by "acetyl nitrate" (nitric acid – acetic anhydride) occur selectively in the 4-position of the pyrazole ring, as do brominations of I and II in chloroform solution. These results are in agreement with R. D. Brown's calculations of localization energies for electrophilic substitution in pyrazole.However, nitration of I by mixed acids at 12° yields 1-p-nitrophenylpyrazole, and bromination of I by bromine in concentrated sulphuric acid in the presence of silver sulphate yields 1-p-bromophenylpyrazole.The variations in orientation of substitution can be rationalized if the reacting species of I in strongly acidic solvents is the conjugate acid, in which the pyrazole ring is deactivated by protonation.

NITROLYSIS OF HEXAMETHYLENETETRAMINE: II. NITROLYSIS OF l,5-ENDOMETHYLENE-3,7-DINITRO-1,3,5,7-TETRAZA-CYCLOÖCTANE (DPT)

1949 ◽  
Vol 27b (5) ◽  
pp. 462-468 ◽  
Author(s):  
A. F. McKay ◽  
George F Wright ◽  
H. H. Richmond
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Ammonium Nitrate ◽  
Acid Anhydride ◽  
Nitrogen Pentoxide ◽  
Linear Poly ◽  
Acetyl Nitrate ◽  
Nitrate Mixture

When 1,5-enedomethylene-3,7-dinitro-1,3,5,7-tetrazacycloöctane (DPT) is nitrolyzed with nitric acid – ammonium nitrate mixture the products are cyclic trimeric and tetrameric methylenenitramines (RDX and HMX). When the ammonium nitrate in this nitrolysis mixture is replaced by anhydrides such as nitrogen pentoxide or acetic anhydride then terminally esterified linear poly-methylenenitramines such as 1,9-dinitroxy-2,4,6,8-tetranitro-2,4,6,8-tetrazanonane and the 1,9-diacetoxy analogue respectively are obtained. Replacement of this nitric acid – anhydride mixture by acetyl nitrate does not produce the same type of nitrolysis. It is therefore concluded that nitric acid and an anhydride act independently, the former as a nitrolyzing agent and the latter as an esterifying agent. Alternatively the presence of ammonium nitrate serves to promote esterification and/or promote demethylolation.

scholarly journals Nitration of Hydrolysis Lignin in Water-Aprotic Solvent Mixtures

2020 ◽  
pp. 184-192
Author(s):  
D.E. Lakhmanov ◽  
◽  
Yu.G. Khabarov ◽  
V.A. Veshnyakov ◽  
M.R. Yokubjanov
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Dimethyl Sulfoxide ◽  
Nitrogen Content ◽  
Aprotic Solvent ◽  
Maximum Yield ◽  
Hydrolysis Lignin ◽  
Solvent Mixtures ◽  
Constant Weight ◽  
Acetyl Nitrate

Industrial lignins are formed from native lignins during chemical or biochemical processing of plant raw materials. Lignins can be modified to produce valuable products, including monomers, polymeric materials, and composites. The article presents the results of a study of hydrolysis lignin nitration under various conditions. The aim of the study was to obtain a nitrated hydrolysis lignin with a maximum yield and maximum nitrogen content. Therefore, the nitration was carried out using nitric acid in a water-aprotic solvent binary mixtures (1,4-dioxane, dimethyl sulfoxide, tetrahydrofuran, dimethylformamide, acetonitrile). Acetyl nitrate, which is a mixed anhydride of nitric and acetic acids, was also used as a nitrating agent. In this regard, the consumption of acetic anhydride in the synthesis of acetyl nitrate was used taking into account the water present in concentrated nitric acid. Acetyl nitrate was obtained by the reaction of acetic anhydride and concentrated nitric acid at room temperature for 30 min. Acetyl nitrate is a mild nitrating agent opposed to nitric acid. Nitration was carried out under reflux in a boiling water bath for 2–5 min (with nitric acid) or 1–60 min (with acetyl nitrate). Upon completion of the nitration reaction, the products were filtered, washed with distilled water and dried to constant weight without heating. When nitration was performed with nitric acid, the maximum yield of nitrated hydrolysis lignin (83–101 %) was achieved using 1,4-dioxane, acetonitrile, and tetrahydrofuran; and the maximum nitrogen content (4.3–4.5 %) was achieved using 1,4-dioxane or acetonitrile. The use of dimethyl sulfoxide and dimethylformamide leads to a decrease in the product yield to 23–35 %, to a lower nitrogen content of 1.3–3.9 % and an increased oxygen content, which indicates the occurrence of not only nitration, but also depolymerization and oxidative transformations. When nitration with acetyl nitrate, the reaction takes place for 1–3 min, herewith the product contains up to 4.7 % of nitrogen. On the IR spectra of nitrated hydrolysis lignins, new absorption bands appear at 1555 and 1710 cm–1 due to the appearance of carboxyl and nitro groups.

Selective Nitroxylation of Adamantane Derivatives in the System Nitric Acid–Acetic Anhydride

2020 ◽  
Vol 56 (9) ◽  
pp. 1532-1539
Author(s):  
Yu. N. Klimochkin ◽  
E. A. Ivleva ◽  
I. K. Moiseev
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Adamantane Derivatives

STUDIES ON LIGNIN AND RELATED COMPOUNDS: IV. THE NITRATION OF GLYCOL-LIGNIN

1930 ◽  
Vol 3 (2) ◽  
pp. 130-139 ◽  
Author(s):  
Harold Hibbert ◽  
Leo Marion
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Nitro Group ◽  
Nitroso Compound ◽  
Initial Oxidation ◽  
Percentage Composition ◽  
Acidic Component ◽  
Fuming Nitric Acid ◽  
Related Compounds

Glycol-lignin at temperatures below 0 °C., dissolves completely in a mixture of four parts of acetic anhydride and one part of fuming nitric acid, giving rise to a 125% yield of a product (nitrated-lignin) which has undergone nitration and acetylation. The nitrogen in the product is present partly in the form of a nitro group, an ester of nitric acid, a nitroso compound and in another form not yet determined. A further treatment of this nitrated-lignin with a nitrating liquor of the same composition, followed by heating at 80 °C. causes a short initial oxidation, and yields a substance differing slightly from the first and having a C:H ratio almost 1:1. Repetition of the treatment does not seem to alter the percentage composition appreciably, until after the fourth treatment.Nitrated-lignin can be methylated, the methoxyl content of the product being more than double that of the original nitrated-lignin. It can also be reduced, the resulting product diazotized and coupled with β-naphthol disulphonic acid.The soluble products of the nitration reaction contain an acidic component which has not been identified.

Sign in / Sign up

Export Citation Format

Share Document