- Conformations, equilibrium thermodynamics and rotational barriers of secondary thiobenzanilides
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The article deals with conformational behaviour of 2-methoxy-2′-hydroxythiobenzanilides. The CS-NH group of these compounds preferentially adopts the Z-conformation. Entropy favours the Z-conformer over the E-conformer, whereas enthalpy slightly favours the E-conformer over the Z-conformer. The rotational barrier about the CS-NH bond was determined to be (81.5±0.4) kJ/mol. No significant rotational barrier was found on the Ar-CS and Ar-NH bonds. All experimental outcomes are compared with the results of quantum-chemical calculations.
- Kozic, Ján,Novák, Zdeněk,?ímal, Václav,Profant, Václav,Kune?, Ji?í,Vin?ová, Jarmila
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p. 2072 - 2083
(2016/04/09)
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- Highly efficient, para-selective oxychlorination of aromatic compounds using potassium chloride and Oxone
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A highly efficient, regioselective method for oxychlorination of aromatic compounds is possible through electrophilic substitution of chlorine generated in situ from KCl as a chlorine source and Oxone as an oxidant for the first time.
- Narender,Srinivasu,Kulkarni,Raghavan
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p. 279 - 286
(2007/10/03)
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- Bis(dealkoxycarbonylation) of nitroarylmalonates: A facile entry to alkylated nitroaromatics
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A simple approach to alkylated nitroaromatics from substituted nitroaryl malonic esters by double decarboxylation is detailed.
- Gurjar,Reddy,Murugaiah,Murugaiah
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p. 1659 - 1661
(2007/10/03)
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- Iron(III)-catalysed nitration of non-activated and moderately activated arenes with nitrogen dioxide-molecular oxygen under neutral conditions
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In the presence of molecular oxygen and a catalytic amount of tris(pentane-2,4-dionato)iron(III), non-activated and moderately activated arenes, which include alkylbenzenes, halogenobenzenes, phenolic ethers, naphthalene and derivatives, can be nitrated with nitrogen dioxide at ice-bath temperature or below to give the corresponding nitro derivatives in fair to good yields. An electron-transfer mechanism has been proposed, where an activated NO2-FeIII complex plays a key role in the cyclic process for converting arenes into nitroarenes.
- Suzuki, Hitomi,Yonezawa, Shuji,Nonoyama, Nobuaki,Mori, Tadashi
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p. 2385 - 2389
(2007/10/03)
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- A veterinary medicament for preventive treatment and therapy of cattle against parasites
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A veterinary medicament to control endo- and ectoparasites including larvae of arthropoda, for oral and parenteral therapeutical and prophylactical application, consisting of Ivermectin and N-[5-chloro-4-α-chlorophenyl-α cyano-methyl-2-methyl-phenyl-]-2-hydroxy-3,5-diiodobenzamide.
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- Nitration of p-Chlorotoluene and p-Chloroisopropylbenzene
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The nitrations of p-chlorotoluene and p-chloroisopropylbenzene with nitric acid in acetic anhydride have been studied.The product composition from the nitration of p-chlorotoluene in acetic anhydride when examined alongwith the previously known product compositions obtained from the nitrations of p-chlorotoluene in varying percentages of sulphuric acid gave information of the degree of attack by the nitronium ion at various positions in p-chlorotoluene.The relative rates of nitrations at various nuclear positions for chlorobenzene could then be calculated.Results from nitration of p-chloroisopropylbenzene were found to be in agreement with these values.
- Khan, Iftikhar A.,Manglik, Ajay K.,Sangal, S. K.
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p. 415 - 416
(2007/10/02)
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- ipso Nitration. XXVIII. Nitration of 4-substituted toluenes: 1,2 adducts
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Nitration of 4-acetamido, 4-chloro, and 4-methoxy-toluene in acetic anhydride gives in each case a cis 1,2 nitronium acetate adduct in adition to the nitro substitution product(s).Nitration of 4-fluorotoluene gives a pair of diastereomeric 1,4 nitronium acetate adducts and the cis 1,2 adduct.
- Fisher, Alfred,Fyles, Deborah L.,Henderson, George, N.,Mahasay, Sumit Ray
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p. 1764 - 1770
(2007/10/02)
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- Electrophilic Aromatic Substitution. Part 30. The Kinetics and Products of the Solvolyses in Aqueous Sulphuric Acids of 5-Chloro-2-methyl-2-nitrocyclohexa-3,5-dienyl Acetate: the Occurence of AAC2 and AAl1 Solvolyses, and of an Acid-catalysed Elimination of Nitrous Acid, and the...
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Good first order kinetics of solvolysis of the above-named diene in water and in 6.5-43.6percent H2SO4 at 25 deg C, and in water and in 15.2-58.8percent H2SO4 at 5 deg C have been observed.The yields of 4-chlorotoluene, 5-chloro-2-methylphenyl acetate, 5-chloro-2-methylphenol, 4-chloro-2-nitrotoluene, 4-chloro-3-nitrotoluene, and 4-methyl-2-nitrophenol produced in water and in 21.5-92.4percent H2SO4 at 25 deg C in the presence of sulphanilic acid or hydrazinium sulphate, and additionally of 2- and 4-nitroanisole when anisole was also added, have been measured.The solvolysis proceeds by an acid-catalysed elimination of nitrous acid (confirming a tentative conclusion in another case), which competes with AAC2 and AAL1 ester solvolyses.With increasing acidity the solvolyses become dominant, the AAL1 reaction increasingly so.The small yield of 4-chloro-3-nitrotoluene comes from a thermal reaction of the diene unrelated to the elimination and solvolyses.The AAL1 reaction generates the ipso-Wheland intermediate (WiMe) that is also formed in the nitration of 4-chlorotoluene.The intermediate reacts by return to 4-chlorotoluene and nitronium ion (which can be captured by anisole), by 1,2-and 1,4-nucleophilic capture by water (giving 5-chloro-2-methylphenol and 4-methyl-2-nitrophenol, respectively), and by 1,2-rearrangement to 4-chloro-2-nitrotoluene.The first of these reactions never accounts for more than about 12percent of the WiMe and competition between capture and rearrangement moves strongly in favour of the latter with increasing acidity.Re-examination of the nitration of 4-chlorotoluene has revealed products arising from 1,2- and 1,4-capture of WiMe, previously overlooked.An improved assessmentof positional reactivities shows 59percent of primary attack by nitronium ion to occur at C-Me in 63percent H2SO4.
- Bloomfield, Colin,Moodie, Roy B.,Schofield, Kenneth
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p. 1793 - 1802
(2007/10/02)
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- ipso-Nitration: Formation of Nitronium Acetate Adducts in the Nitration of p-Acetamido-, p-Halogeno-, and p-Methoxy-toluenes, and α-p-Tolyloxyisobutyric acid
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Low-temperature nitration of the title compounds in acetic anhydride gives 1,2-nitronium acetate adducts, except p-fluorotoluene which gives both 1,2 and 1,4 adducts and α-p-tolyloxyisobutyric acid which gives a spiro adduct.
- Fischer, Alfred,Fyles, Deborah L.,Henderson, George N.
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p. 513 - 514
(2007/10/02)
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- 2-Aryl-3,4-diphenylisoxazolin-5-ones
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Contacting of appropriately substituted nitrosobenzene with diphenylcyclopropenone under reflux conditions yields novel 2-aryl-3,4-diphenylisoxazolin-5-ones, which are useful as pharmacological agents in view of their serum triglyceride and cholesterol lowering properties.
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