2- Alkyl-6-methyl pyridine synthesis

Activation of alkyl substituents is illustrated by the synthesis of the isomeric pentylpyridines (Expt 8.33) and ethyl 2-pyridylacetate (Expt 8.32, cognate preparation). Thus removal of a proton from the 2-methyl group of 2-methyl-pyridine (2-picoline) with the aid of base (e.g. sodamide) gives a mesomerically... 

In 1959, Balaban and Nenitzescu reported their work on the preparation of pyrylium salts that followed an earlier report by Praill7 This process is often referred to as the Balaban-Nenitzescu-Praill synthesis and is an efficient method for the preparation of alkyl substituted pyrylium salts and therefore alkyl substituted pyridines. The process involves the diacylation of olefins and has become a common method for the synthesis of 2,4,6-trialkylsubstituted pyrylium salts with identical substituents in the 2- and 6-positions. Stang reported an improved procedure to prepare 2,6-d -tert-butyl-4-methylp3ridine (17) from the corresponding 2,6-di-tert-butyl-4-methyl-pyrylium triflate salt (16) in 1976. ... 

With the catalysis of strong Lewis acids, such as tin(IV) chloride, dipyrromethenes may aiso be alkylated. A very successful porphyrin synthesis involves 5-bromo-S -bromomethyl and 5 -unsubstituted 5-methyl-dipyrromethenes. In the first alkylation step a tetrapyrrolic intermediate is formed which cyclizes to produce the porphyrin in DMSO in the presence of pyridine. This reaction sequence is useful for the synthesis of completely unsymmetrical porphyrins (K.M. Smith, 1975). 

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... 

Purine, 9- -D-ribofuranosyl-6-selenoxo- 1,6-dihydro-synthesis, 5, 597 Purine, 6-thiocyanato-acylation, 5, 559 Purine, 2-thioxo-synthesis, 5, 589 Purine, 8-thioxo-iodination, 5, 559 synthesis, 5, 577, 597 Purine, 2-thioxo-2,3-dihydro-synthesis, 5, 572 Purine, 6-thioxo-1,6-dihydro-acylation, 5, 559 dethiation, 5, 558 halogenation, 5, 559 hydrolysis, 5, 560 methylation, 5, 535 oxidation, 5, 560 synthesis, 5, 572, 596 Purine, 8-thioxo-7,8-dihydro-acylation, 5, 559 Purine, 2,6,8-trichloro-alkylation, 5, 530 amination, 5, 562 reactions, 5, 561, 562 with hydriodic acid, 5, 563 with pyridine, 5, 562 synthesis, 5, 598 Purine, 2,6,8-trichloro-7-methyl-synthesis, 5, 557 Purine, 8-trifluoromethyl-synthesis, 5, 574... 

Pyridine, 3-(dimethylamino)-amination, 2, 236 methylation, 2, 342 nitration, 2, 192 iV-oxide synthesis, 2, 342 Pyridine, 4-(dimethylamino)-in acylation, 2, 180 alkyl derivatives pK, 2, 171 amination, 2, 234 Arrhenius parameters, 2, 172 as base catalysts, 1, 475 hydrogen-deuterium exchange, 2, 286 ionization constants, 2, 172 methylation, 2, 342 nitration, 2, 192 iV-oxide synthesis, 2, 342... 

Attempts to synthesize transition metal alkyl compounds have been continuous since 1952 when Herman and Nelson (1) reported the preparation of the compound C H6>Ti(OPri)3 in which the phenyl group was sigma bonded to the metal. This led to the synthesis by Piper and Wilkinson (2) of (jr-Cpd)2 Ti (CH3)2 in 1956 and a large number of compounds of titanium with a wide variety of ligands such as ir-Cpd, CO, pyridine, halogen, etc., all of which were inactive for polymerization. An important development was the synthesis of methyl titanium halides by Beerman and Bestian (3) and Ti(CH3)4 by Berthold and Groh (4). These compounds show weak activity for ethylene polymerization but are unstable at temperatures above — 70°C. At these temperatures polymerizations are difficult and irreproduceable and consequently the polymerization behavior of these compounds has been studied very little. In 1963 Wilke (5) described a new class of transition metal alkyl compounds—x-allyl complexes,... 

Hydrolytic reactions can also be applied in the synthesis of aldehydes or ketones via the corresponding 1,3-oxazine derivatives. The anion formed from 3-methyl-2-(4-pyridyl)tetrahydro-l,3-oxazine 155 on treatment with BuLi proved to react with various electrophiles (alkyl halides, carboxylic esters, acid chlorides, or aldehydes) exclusively at position 2 of the 1,3-oxazine ring and not at the pyridine nitrogen atom. The readily formed 2,2-disubstituted-l,3-oxazine... 

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