Free Radical Alkylation

Guanine, 9-/3-D-ribofuranosyl-, 5, 536 Guanine, 6-thio-tautomerism, 5, 509 toxicity, 1, 141 Guanine, 8-trifluoromethyl-synthesis, 5, 574 Guanines, thio-synthesis, 5, 572 Guanosine arylation, 5, 538 dipole moment, 5, 522 free radical alkylation, 5, 543 hydrobromide... 

UV spectra, 5, 517 bromination, 5, 540 dipole moment, 5, 523 free radical alkylation, 5, 543 free radical methylation, 5, 544 IR spectra, 5, 518, 519 irradiation, 5, 543 mass spectra, 5, 519 metabolism, 1, 234 monoprotonated tautomerism, 5, 509 oxidation, 5, 539 1-oxides... 

Beyer synthesis, 2, 474 electrolytic oxidation, 2, 325 7r-electron density calculations, 2, 316 1-electron reduction, 2, 282, 283 electrophilic halogenation, 2, 49 electrophilic substitution, 2, 49 Emmert reaction, 2, 276 food preservative, 1,411 free radical acylation, 2, 298 free radical alkylation, 2, 45, 295 free radical amidation, 2, 299 free radical arylation, 2, 295 Friedel-Crafts reactions, 2, 208 Friedlander synthesis, 2, 70, 443 fluorination, 2, 199 halogenation, 2, 40 hydrogenation, 2, 45, 284-285, 327 hydrogen-deuterium exchange, 2, 196, 286 hydroxylation, 2, 325 iodination, 2, 202, 320 ionization constants, 2, 172 IR spectra, 2, 18 lithiation, 2, 267... 

Quinolinium 2-dicyanomethylene-1,1,3,3-tetracyanopropanediide dimensions, 2, 110 Quinolinium iodide, 1-alkyl-Ladenburg rearrangement, 2, 300 Quinolinium iodide, 1-methyl-Ladenburg rearrangement, 2, 300, 335 Quinolinium iodide, [l-methyl-4-[3(5)-pyrazolyl]-blood sugar level and, 5, 291 Quinolinium perchlorate, 1-ethoxy-hydroxymethylation, 2, 300 Quinolinium perchlorate, 1-methyl-nitration, 2, 318 Quinolinium salts alkylation, 2, 293 Beyer synthesis, 2, 474 electrophilic substitution, 2, 317 free radical alkylation, 2, 45 nitration, 2, 188 reactions... 

Goldschmidt and Minsinger " isolated some of the products formed during the decomposition of several diacyl peroxides in pyridine (Table IV). The yields obtained are so far the highest reported for any free-radical alkylation. 

FREE-RADICAL ALKYLATION OF QUINONES 2-PHENOXYMETHYL-l,4-BENZOQUINONE... 

The reaction is a free-radical alkylation in which radicals are derived from a carboxylic acid by decarboxylation with Ag+/S20a-. If has the advantage that the reaction medium can be adjusted so that the monoalkylatcd product precipitates as it is formed, whereby di- or polyalkylation5 is suppressed. 

Even more pronounced steric effects have been observed for the free radical alkylation of protonated N-heterocyclic bases by the procedure of Minisci69, b d. Quinoline is attacked selectively in the 2- and 4-position by nucleophilic alkyl radicals in sulfuric acid. The largest radicals, t.-butyl, react exclusively in the 2-position because of steric hindrance by the peri-hydrogen when attack occurs at the 4-position. 

Even more pronounced steric effects have been observed for the free radical alkylation of protonated N-heterocyclic bases by the procedure of Minisci ... 

Table 25 Free Radical Alkylation and Arylation of Pyridines3... 

For reviews of the free-radical alkylation of aromatic compounds, see Ticcco Tcsiaferri React. Intermed. 

Most transformations studied so far in this field are considered to be free radical reactions, usually chain reactions. Free radical alkylation reactions have been reviewed recently, (40, 70, 78) and therefore will not be treated here. We shall discuss the free radical aspects as far as they are related to the problems with which we are concerned. 

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