Pyridine 2-methyl

C19H2 eCrN203, (2SR,2 SR)-Tricarbonyl[5-ethyl-2-(5 -ethyl-1 ,2 ,3 ,4 -tetrahydro-1 -methyl-2 -pyridyl)-1,6-dihydro-1-methyl-pyridine Jchromium, 46B, 930... 

Here again the question of reactive species in the acidic medium remains open. It must be noted that bromination of 2-amino-5-methyl-pyridine (pK = 7) and 2-amino-5-nitropyridine (pJC = 2.8) in N sulfuric acid takes place on the free base (443). 

Of the total tar bases in U.K. coke-oven and CVR tars, pyridine makes up about 2%, 2-methyl pyridine 1.5%, 3- and 4-methylpyridines about 2%, and ethylpyridine and dimethylpyridines 6%. Primary bases, anilines and methylanilines, account for about 2% of the bases in coke-oven and CVR tars and 3.5% of the bases in low temperature tars. The main basic components in coke-oven tars are quinoline (16—20% of the total), isoquinoline (4—5%), and methyl quinolines. These dicycHc bases are less prominent in CVR and low temperature tars, in which only a minority of the basic constituents have been identified. 

The bicyclic nature of the labile adduct (79) from 3-methyl-pyridine was established by Acheson and Taylor who found that hydrogenation, yielding (80), followed by oxidation gave pyridine-3,4,5-tricarboxylic acid. This conclusion is consistent with Diels and Alder s observations that acid hydrolysis of the labile pyridine adduct gave pyridine and some crotonaldehyde, whereas alkaline hy-... 

The indirect deactivation in 2-amino-4-chloroquinoline (187) requires vigorous conditions (potassium hydroxide in hot ethylene glycol, or boiling propanolic propoxide for 16 hr) to displace the chloro group, which is stable to aqueous alkali and to hydriodic acid. The direct deactivation in 5-amino-2-chloro-3-cyano-6-methyl-pyridine (188) prevents reaction with alkoxide ion under conditions which produce smooth reaction of the des-amino analog. 

Four 2-substituted pyridines were found to give the expected 6,6 -disubstituted 2,2 -bipyridines in yields corresponding to only about 3% of the amount of 2,2 -bipyridine formed from pyridine itself under comparable conditions. It is also of interest that with three 2-methyl-pyridines the expected 6,6 -dimethyl-2,2 -bipyridines were accompanied by smaller amounts of 2,2 -bipyridines having no methyl groups in the 6,6 -positions. Moreover, a very small amount of 5,5 -dimethyl-2,2 -bipyridine (8) was isolated following reaction with 2,5-lutidine (6) but no 3,3 -dimethyl-2,2 -bipyridine could be detected. The absence of this compound suggests that 3,3, 6,6 -tetramethyl-2,2 -bipyri-dine (9) is not an intermediate, but that the 2-methyl group is lost before the formation of the 2,2 -bipyridine (6—>8). 

The combined liquors, which comprise an aqueous hydrochloric acid solution of 3-amino-methyl-pyridine hydrochloride, are then heated to a temperature of 60° to 65°C, and ethyl nitrite gas is passed into the heated solution. The ethyl nitrite is generated by placing 20 liters of 90% ethyl alcohol in a suitable vessel, diluting with 200 liters of water, and, while stirring, adding to the dilute alcohol 18.3 kg of nitrosyl chloride at the rate of 2.25 kg per hour. (The process using methyl nitrite is carried out by substituting a stoichiometrically equivalent quantity of methyl alcohol for the ethyl alcohol.)... 

Although iodides are more reactive than bromides, 2-(trifluoro-methyl)pyridine was obtained in 95% yield from 2-bromopyridine and CF3Br using an undivided electrochemical cell, DMF, and a sacrificial copper anode. CF3Cu was the reactive intermediate (92CC53). Photochem-... 

The influence of different additives on the apparent pKa values of diphenylmethane, 4-methyl-pyridine and the deprotonation rate of triphenylmethane was investigated 3 TM EDA caused the highest enhancement. 

Unsaturated nitriles Dicyanobutenes Methyl pyridines Ethyl disulfides (HSSH) Acrylonitrile dimers... 

Auch bei der Reduktion von 3-Hydroxy-2-methyl-pyridin-4,5-dicarbonsaure-dime-thylester mit Natriumboranat/Aluminiumchlorid bei 20° in Gegenwart eines Alumini-umchlorid-Uberschusses wird in 57%iger Ausbeute 3-Hydroxy-2-methyl-4-hydroxyme-thyl-pyridin-5-carbonsaure-4 -lacton erhalten3. 

Analog lassen sich Carbonsaure-ester mit 1,5- Mol-Aquiv. Natriumboranat in Gegenwart von 1 Mol-Aquiv. Benzanilid in 2-Methyl-pyridin bei 100°in 5-6 Stdn. zu Alkoholen reduzieren" [z.B. Herstellungvon Octanol (74% d.Th.), Nonanol (87% d.Th.) und 4-Cyano-benzylalkohol (89% d.Th.)]. 

Entsprechend wird 4-Chlor-2-methyl-pyridin zu 79% d.Th. erhalten1. 

Pyridin-carbonsauren (z. B. Isonicotinsaure, Methyl-pyridin-carbonsauren, jedoch nicht Nicotinsaure) lassen sich selektiv mittels einer waBrigen Chrom(II)-Salzlosung in ei-nem organ. Losungsmittel in Gegenwart von Protonen zu den entsprechenden Aldehy-den reduzieren3 ... 

Pyridin-, Chinolin- und N,N-Dimethyl-anilin-N-oxid werden elektrolytisch an Queck-silber in Methanol/Tetramethylammoniumchlorid zu Pyridin (81% d.Th.), Chinolin (78% d.Th.) bzw. N,N-Dimethyl-anilin (78% d.Th.) (galvanostat. bei 5 A/65°C) redu-ziert1. Analog verhalten sich 2- und 4-Methyl-pyridin-N-oxide (2-Methyl-pyridin 96% 4-Meihyl-pyridin 80% d.Th.)1. 

Fluorobenzene to fluorodihydrocatechol and fluorocatechol Conversion of 2,5-dimethyl pyrazine to 5-metyl pyrazine-2-carboxylic acid, conversion of 5-ethyl-2-methyl pyridine to... 

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