Imidazo pyridine, alkylation

Imidazo[4,5-6]pyridine, 1,2-dimethyl-methylation, 5, 618 Imidazo[4,5-6]pyridine, 2,3-diphenyl-synthesis, 5, 636 Imidazo[4,5-6]pyridine, 6-halo-alkylation, 5, 616 aminomethylation, 5, 616 Imidazo[4,5-6]pyridine, 2-(4-hydroxy-6-methylpyrimidin-2-ylamino)-synthesis, 5, 637... 

Imidazo[4,5-c]pyridine, 2,3-dimethyl-radical alkylation, 5, 621 Imidazo[4,5-c]pyridine, 2-ethoxy-synthesis, 5, 635... 

Imidazo[4,5-/ ]pyridines are exclusively hydroxylated in the imidazole ring however, no yield was reported (Equation 3) . N-Alkylation, N-deprotection, palladium-catalyzed cross-coupling, and thionation of imidazo[4,5-/ ]pyridines were reviewed in <1996CHEC-II(7)283>. 

Imidazolium ligands, in Rh complexes, 7, 126 Imidazolium salts iridium binding, 7, 349 in silver(I) carbene synthesis, 2, 206 Imidazol-2-ylidene carbenes, with tungsten carbonyls, 5, 678 (Imidazol-2-ylidene)gold(I) complexes, preparation, 2, 289 Imidazopyridine, in trinuclear Ru and Os clusters, 6, 727 Imidazo[l,2-a]-pyridines, iodo-substituted, in Grignard reagent preparation, 9, 37—38 Imido alkyl complexes, with tantalum, 5, 118—120 Imido-amido half-sandwich compounds, with tantalum, 5,183 /13-Imido clusters, with trinuclear Ru clusters, 6, 733 Imido complexes with bis-Gp Ti, 4, 579 with monoalkyl Ti(IV), 4, 336 with mono-Gp Ti(IV), 4, 419 with Ru half-sandwiches, 6, 519—520 with tantalum, 5, 110 with titanium(IV) dialkyls, 4, 352 with titanocenes, 4, 566 with tungsten... 

A related intramolecular N-alkylation leading to saturated nitrogen heterocycles 99 can proceed via dehydration of intermediates 98 (Eq. 39) [96]. Unsaturated nitrogen heterocycles such as pyrroles [97], indoles [98], benzo-azoles [99], 2,3-dihydroimidazol-2-ones [100], and imidazo[l,2-a]pyridines [101] were obtained through similar cyclocondensation reactions. Interesting ruthenium-catalyzed syntheses of quinolines have been achieved by means of cyclocondensations of aniline derivatives with propanediols, aminoalcohols, or... 

Using standard alkylating conditions, a series of imidazo[4,5-h]pyridines (107) were alkylated exclusively at N-3 to give the derivatives (108) (Equation (1)) <91JMC2919>. 

Substituted imidazo[4,5-c]pyridin-2-ones such as compound (149) upon reaction with iodo-methane gave intractable mixtures rather than the desired product (150). To prepare compound (150) one must first /V-alkylate the imidazole (151) and subsequently annulate <93JMC1341>. 

KGS570, 73KGS1686). Alkylation of 3-substituted imidazo[4,5-h]pyridin-2(liT)-ones... 

O-Alkylation of imidazo[4,5-h]pyridin-2-ones (110) sometimes occurs on treatment with alkyl halides or diazomethane <78H(iO)24l, 78JHC937), and one instance of O- as well as A-acetylation as in (111) has been reported (the position of the A-acetyl group was not firmly established) (59JOC1455). 

Radical alkylation of 1-methyl-, 3-methyl- and 2,3-dimethyl-imidazo[4,5-c]pyridine (147) takes place at C-4 giving (148) with some dimethylation of monomethyl compounds occurring, the second methylation being at C-2 (77KGS933, 78MI41006). 

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