Ipso nitration. XIX. Formation of cyclohexadiene adducts from nitration of 4-ethyltoluene and 1,4-diethylbenzene in nitric acid and acetic anhydride

1978 ◽  
Vol 31 (6) ◽  
pp. 1241 ◽  
Author(s):  
A Fischer ◽  
GN Henderson ◽  
RJ Thompson
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Trifluoroacetic Acid ◽  
Trifluoroacetic Anhydride ◽  
Phenyl Acetate ◽  
Aqueous Methanol ◽  
Methyl Phenyl

Nitration of 4-ethyltoluene in acetic anhydride at -20° gives the diastereoisomers of 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dienyl acetate and of 4-ethyl-1-methyl-4-nitrocyclohexa-2,5-dienyl acetate. Similar nitration of 1,4-diethylbenzene gives the diastereoisomers of 1,4-diethyl-4-nitro-cyclohexa-2,5-dienyl acetate. Rearomatization of the adducts of p-ethyltoluene in trifluoroacetic acid-trifluoroacetic anhydride gives 4-ethyl-2-nitrotoluene from the 1-ethyl-4-methyl-4- nitro isomers and 4-ethyl-3-nitrotoluene from the 4-ethyl-1-methyl-4-nitro isomers. In aqueous methanol 2-ethyl- 5-methylphenyl acetate is obtained from the 1-ethyl-4-methyl-4-nitro isomers and 5-ethyl-2- methyl-phenyl acetate from the 4-ethyl-1-methyl-4-nitro isomers.

Reactions of phenyl-substituted heterocyclic compounds. VII. Reagent-dependent orientation in the nitration of 4-phenylpyrimidine

1967 ◽  
Vol 45 (13) ◽  
pp. 1431-1437 ◽  
Author(s):  
Brian M. Lynch ◽  
Lizzie Poon
Keyword(s):  
Nitric Acid ◽  
Acetic Anhydride ◽  
Nucleophilic Addition ◽  
Heterocyclic Compounds ◽  
Trifluoroacetic Anhydride ◽  
Reaction Products ◽  
Heterocyclic Nitrogen

In the nitration of 4-phenylpyrimidine, the nature of the reaction products is strongly dependent upon the nitrating reagent. Mixed nitric and sulfuric acids yield 4-o- and 4-m-nitrophenylpyrimidines in the ratio 2:3, whereas nitric acid – trifluoroacetic anhydride yields 4-o-, 4-m-, and 4-p-nitrophenylpyrimidines in the ratio 45:29:26, and nitric acid – acetic anhydride yields 2,4-diacetoxy-1,3,5-trinitro-6-phenyl-1,2,3,4-tetrahydropyrimidine.An explanation of these findings involves the possibility of the addition of nitronium ion at the heterocyclic nitrogen, followed in some circumstances by nucleophilic addition.

ipso Nitration. XXIII. Reactions of cyclohexadiene adducts from nitration of 4-ethyltoluene in acetic anhydride

1981 ◽  
Vol 59 (15) ◽  
pp. 2314-2327 ◽  
Author(s):  
Alfred Fischer ◽  
George N. Henderson
Keyword(s):  
Sulfuric Acid ◽  
Acetic Anhydride ◽  
Methyl Iodide ◽  
Methyl Ether ◽  
Potassium Hydroxide ◽  
Silver Oxide ◽  
Aluminum Hydride ◽  
Trifluoroacetic Anhydride ◽  
Aqueous Methanol

The diastereoisomers of 4-ethyl-1-methyl-4-nitrocyclohexa-2,5-dienyl acetate (1) and 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dienyl acetate (2) are stereospecifically reduced to the corresponding nitrocyclohexadienols with aluminum hydride. Each dienol is stereospecifically methylated to the corresponding methyl ether with methyl iodide, silver oxide, and potassium hydroxide. Acid-catalysed solvolysis of the acetates 1 and 2 results in the substitution of the acetate moiety by other nucleophiles and these reactions are not stereospecific. The products of rearomatization of dienyl acetates, dienols, and dienyl methyl ethers depend on the acidity and ionizing power of the solvents and are readily explained in terms of reactions involving a nitrocyclohexadienyl cation or acetoxy- (hydroxy-, methoxy-)cyclohexadienyl cation as key intermediates. In the 4-acetoxy-4-alkylcyclohexadienyl cation 1,2-migration of the acetoxyl group is more rapid than alkyl migration, but 1,2-alkyl migration is faster than migration of the hydroxyl or methoxyl groups in the corresponding cations. 1-Ethyl-4-methoxy-4-methylcyclohexa-2,5-dien-1-ol and 4-ethyl-3-nitrotoluene are significant minor products in the solvolysis of 1-ethyl-4-methyl-4-nitrocyclohexa-2,5-dien-1-ol in aqueous methanol. Nitration of p-ethyltoluene in the presence of sulfuric acid or in trifluoroacetic anhydride gives a mixture of 4-ethyl-2-nitro- and 4-ethyl-3-nitrotoluene in a 2:1 ratio.

Synthesis of Cyclic Nitramines From Products of the Cyclocondensation Reaction of Guanidine With 2,3,5,6-Tetrahydroxypiperazine-1,4-dicarbaldehyde

1994 ◽  
Vol 47 (11) ◽  
pp. 2033 ◽  
Author(s):  
IJ Dagley ◽  
JL Flippenanderson
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Acetic Anhydride ◽  
Formic Acid ◽  
Guanidine Hydrochloride ◽  
Chloride Ion ◽  
Trifluoroacetic Anhydride ◽  
Cyclocondensation Reaction ◽  
Cyclic Nitramines ◽  
Cis Isomer

The reaction of 2,3,5,6-tetrahydroxypiperazine-1,4-dicarbaldehyde (1) with guanidine hydrochloride in hydrochloric acid can be controlled to give 2,6-diiminododecahydrodiimidazo[4,5-b:4′,5′-e] pyrazine (2a) or the cis isomer of 4,5-diamino-2-iminoimidazolidine (4). Compound (4) reacts with formaldehyde, or formic acid followed by reduction, to give 2-iminooctahydroimidazo[4,5-d] imidazole (7). Treatment of (2a) or (7) with nitric acid gives dinitro derivatives that were isolated as nitric acid salts of the cyclic guanidines. Reaction of the dinitro derivatives with nitric acid/acetic anhydride in the presence of chloride ion gives 4,8-dinitro-2,6-bis( nitroimino ) dodecahydrodiimidazo -[4,5-b:4′,5′-e] pyrazine (3a) and 1,3-dinitro-5-( nitroimino ) octahydroimidazo [4,5-d] imidazole (9). The reaction of (7) with nitric acid/ trifluoroacetic anhydride was controlled to give either the tetranitro or a dinitro bis ( trifluoroacetyl ) derivative of the corresponding bicyclic urea.

Acetylation and Formylation of 3-Ferrocenylpyrroles

1999 ◽  
Vol 64 (1) ◽  
pp. 99-106
Author(s):  
Battsengel Gotov ◽  
Štefan Toma ◽  
Eva Solčániová
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Aluminum Chloride ◽  
Acetyl Chloride ◽  
Trifluoroacetic Anhydride ◽  
Acid Mixture ◽  
Chloride Method

Acetylations of 3-ferrocenyl-1-methylpyrrole as well as 3-cyano-4-ferrocenylpyrrole and 3-cyano-4-ferrocenyl-1-methylpyrrole were performed. The course of the acylation is highly dependent on the acylation agent, that is acetyl chloride/aluminum chloride (method A), trifluoroacetic anhydride-acetic acid mixture (method B) or acetic anhydride/Sc(OTf)3 (method C). Method A gives the acetylation on ferrocene moiety, method B affords the trifluoroacetylation on pyrrole moiety and method C affords pyrrole moiety acetylation. Vielsmeier-Haack formylation gives the products of substitution on pyrrole moiety.

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

N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part XIII. Cleavage and Rearrangement Reactions of Pyrazolo[1,5-b][1,2,4,6]thiatriazine 1,1-Dioxides

2016 ◽  
Vol 69 (1) ◽  
pp. 61 ◽  
Author(s):  
Rebecca E. Norman ◽  
Michael V. Perkins ◽  
Andris J. Liepa ◽  
Craig L. Francis
Keyword(s):  
Ethyl Acetate ◽  
Dimethyl Sulfoxide ◽  
Trifluoroacetic Acid ◽  
Sulfonic Acid ◽  
Trifluoroacetic Anhydride ◽  
Ring Cleavage ◽  
Thermal Rearrangement ◽  
Heterocyclic Synthesis ◽  
Similar Treatment ◽  
Catalytic Hydrogenolysis

Treatment of pyrazolo[1,5-b][1,2,4,6]thiatriazines 1 with the Vilsmeier–Haack reagent afforded pyrazolo[1,5-a][1,3,5]triazines 5. Reaction of compounds 1 with trifluoroacetic anhydride, dimethyl sulfoxide, and triethylamine afforded 5-dimethylsulfanylidene derivatives 8. The guanidino-pyrazole-sulfonic acid 9 was produced from treatment of compounds 1 with trifluoroacetic acid under anhydrous conditions. Similar treatment in the presence of water afforded the desulfonated pyrazolo-guanidine 6. Reactions of 6 with one-carbon electrophiles provided various 4-substituted pyrazolo[1,5-a][1,3,5]triazines 5. Attempted catalytic hydrogenolysis of N7-benzyl pyrazolo[1,5-b][1,2,4,6]thiatriazines 2 in alcohols led to sulfamates 12 from thiatriazine ring cleavage. Ethyl acetate or tert-butanol as solvent allowed successful debenzylation to provide compounds 1. Aminolysis of compounds 2 gave sulfamides 13. Thermal rearrangement of compounds 2 afforded 6-benzyl-pyrazolo[3,4-e][1,2,4]thiadiazines 14.

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