Benzoyl derivatives, protonated

The structural problem was finally cleared up by physical methods, including molar refraction,255-252 and ultraviolet263 and Raman254 spectroscopy. The 3-benzoyl derivative has also been submitted to X-ray analysis.233-235 All the evidence supports a planar fused system of six- and five-membered rings, although some of the earlier work was interpreted in terms of other structures. The proton NMR spectrum of anthranil has been analyzed 265 the parameters are listed in Table A. 

Indole can be nitrated with benzoyl nitrate at low temperatures to give 3-nitroindole. More vigorous conditions can be used for the nitration of 2-methylindole because of its resistance to acid-catalyzed polymerization. In nitric acid alone it is converted into the 3-nitro derivative, but in a mixture of concentrated nitric and sulfuric acids 2-methyl-5-nitroindole (47) is formed. In sulfuric acid, 2-methylindole is completely protonated. Thus it is probable that it is the conjugate acid which is undergoing nitration. 3,3-Dialkyl-3H-indolium salts similarly nitrate at the 5-position. The para directing ability of the immonium group in a benzenoid context is illustrated by the para nitration of the conjugate acid of benzylideneaniline (48). 

Pyrrole, 4-ethynyl-2-formyl-3-methyl-synthesis, 4, 222 Pyrrole, formyl-oxidation, 4, 289 reactions, 4, 292 with sulfoxides, 4, 293 synthesis, 4, 223, 274, 287 Pyrrole, 1-formyl-barrier to rotation, 4, 193 Pyrrole, 2-formyl-benzoylation, 4, 220 conformation, 2, 107 4, 193 diacetoxythallium derivative iodination, 4, 216 dipole moment, 4, 194 ketals, 4, 290 protonation, 4, 47 reactions... 

Stereospecific dependencies of the nonselective relaxation-rates for other protons in a sugar molecule may be seen in the data for a set of 3,4,6-tri-O-acetyl-l-0-benzoyl-2-deoxy-2-bromo-D-hexopyranose derivatives (40-42), as well as other 2-halogeno derivatives. A comparison of their... 

A similar process with benzalacetophenone results in different products, the chemoselectivity being controlled by the experimental conditions, namely the solvent and the supporting electrolyte used [261]. Either an acyclic disulfide, bis(2-benzoyl-l-phenylvinyl) disulfide (in Et0H-DMF/Mg(Cl04)2), or two isomeric thiophenes (in DMF/NaCl04) can thus be obtained (Scheme 63). Upon the substitution of a vinylic proton at C(2) with Br, the reaction becomes more regioselective and the only product now formed is an a,a -dibenzoyl thiophene derivative. 

Other li acetylides Li-C=C-R with R = hexyl [21] or benzylether dendrons [22, 23] (up to the fourth generation) have also been attached to (Figure 3.3), and various different electrophiles have been used to complete the reaction with the intermediate li-fuUeride (Scheme 3.2 and Figure 3.3). Besides the protonation, alkyl-, benzyl-, cycloheptatrienyl-, benzoyl- or vinylether-derivatives or formaldehyde and dichloro-acetylene were used as electrophiles [12,20]. Most of these electrophiles are attached to the anion in the expected C-2 position. The 1,4-adducts are available by quenching the anion with the tropylium cation or benzoyl chloride [12]. The fuUerene anion can be stabilized by introduction of benzylether dendrons. The lifetimes of the anions change with the size of the dendrons [22]. 

AT-Benzoyl-2-hydroxy-2,3-dihydroindoles (192) are additional products resulting from the photolysis of 2-phenylquinoline 1-oxide (193) and its derivatives in ethanol solution.162 These dihydroindoles are also formed by the solvolysis of the corresponding benz[d]-l,3-oxazepines (194) with aqueous ethanol at room temperature, and are therefore interpreted as arising in this way in the photolysis. Quinoline 1-oxide itself undergoes ring contraction166 to IV-formyl-2-hydroxy-2,3-dihydroindole on irradiation in a protonic solvent. 

Imidazole reacts very slowly with singlet oxygen to form the imida-zolidone (86)42S through an elimination reaction involving proton loss and cleavage of the oxygen-oxygen bond of the transannular peroxide (87). On the other hand, 4-phenylimidazole forms a hydantoin derivative (88) and V-benzoyl-V -methoxycarbonylurea (89). This... 

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