2.6- Dimethyl-4-ethylpyridine

Figure 10. Vapor-phase infrared spectrum of basic component Peak A (Figure 9). Component identified as 2,4-dimethyl-6-ethylpyridine. Helium flow rate 10.5 mL/min, 6-sec scan.

Alkylation of 1-indanone with 2-dimethylaminoethyl chloride affords the substituted ketone (1). Condensation with the lithium reagent obtained from 2-ethylpyridine affords the alcohol (2). Dehydration under acidic conditions gives dimethyl-pyrindene (3). ... 

At 15 mm pressure the excess of 2-ethylpyridine is removed, at 120°C/0.5 mm some unreacted 2-(2-dimethylaminoethyl)-indene distills and at 165°-175°C/0.5 mm the 2-(2-dimethyl-aminoethyl)-3-[1-(2-pyridyl)-ethyl]-indene is collected. It may be converted to an aqueous solution of the dihydrochloride by dissolving it in the appropriate amount of dilute hydrochloric acid. 

Chapter V. Quinaldine (V,2) 2-methyl-, 2 5-dimethyl- and 2-acetyl-thiophene (V,8-V,10) 2 5-dimethyl- and 2 4-dimethyl-dicarbethoxy-pyrrole (V,12-V,13) 2-amino- and 2 4-dimethyl-thiazole (V,1 V,16) 3 5-dimethyl-pyrazole (V,17) 4-ethylpyridine (from pyridine) (V,19) n-amyl-pyridines from picolines) (V,28) picolinic, nicotinic and isonicotinic acid (V,21-V,22) (ethyl nicotinate and p-cyanopyridine (V,23-V,24) uramil (V,25) 4-methyl-(coumarin (V,28) 2-hyi ox3depidine (V,29). 

Because PBI is expensive, other thermostable polymers were explored and tested as catalysts (246). A cross-linked version of a polyimide (PI) support with incorporated triazole rings (12b) gave better results than PBI for the epoxidation of cyclohexene. Moreover, it can be reused in the cyclohexene epoxidation at least 10 times without any loss of activity (247). Even less expensive, but thermooxidatively stable materials include polysiloxane-based resins, which have also been used for incorporation of Ti (see Section II,A). In this case, the synthesis comprises the polymerization of TEOS and an oligomeric dimethyl silanol with the addition of functional trialkoxysilanes such as trimethoxysilyl-2-ethylpyridine instead of Ti(OiPr)4 (248). Preliminary results show that the activity per Mo atom is higher than that of PBI-Mo. Furthermore, the degree of leaching of Mo is very low. Thus, it is expected that the polysiloxane-based systems may soon find wide application in oxidation chemistry. 

In addition to 2-methyl-5-ethylpyridine mentioned above, the following dialkylpyridines have been reduced by the Ladenburg method 3,5-dimethylpyridine,58 3-methyl-4-ethylpyridine,48 and 2,4-dimethylpyridine.48 3,5-Dimethyl-3-piperideine (62) and cis- and iratis-3,5-dimethylpiperidine are obtained from 3,5-dimethylpyri-dine.53... 

Methyl-4-ethylpyridine l,3-Dimethyl-4-ethyl-, 1,5-dimethyl-4-ethyl- 62... 

In addition to compounds quoted by Lyle and Anderson," the following quaternary salts have recently been reduced with sodium borohydride ethiodides of pyridine and its homologs, methiodides of 3-ethylpyridine, 4-ethylpyridine, 2-methyl-5-ethylpyridine, and 3-methyl-4-ethylpyridine,102 and the methiodide of 2-benzyl-4-methylpyridine.103 Reductions (NaBH4) of l,2-dimethyl-5-ethyl-pyridinium iodide and l,3-dimethyl-4-ethylpyridinium iodide afford as principal products those 3-piperideines (94, 95) which carry the maximum number of substituents on the double bond, presumably due to hyperconjugation.102... 

Reaction of / -picoline over degassed Raney nickel was found to give 5,5 -dimethyl-2,2 -bipyridine (5), the structure of which was established by its synthesis from 2-bromo-5-methylpyridine.15 Oxidation of this dimethyl-2,2 -bipyridine, and similar oxidation of the diethyl-2,2 -bipyridine derived from 3-ethylpyridine, gave the corresponding dicarboxylic acid and the same acid was produced by the action of degassed Raney nickel on sodium nicotinate (in water) or on ethyl nicotinate.1 15 These transformations established the 5,5 -substitution pattern for three 2,2,-bipyridines derived from 3-substituted pyridines but such evidence is not available for the biaryls... 

Pyridines can be formed by mechanisms other than pyrolysis. The reaction of aldehydes with amino acids has been shown to generate pyridines (50). When a glycine-propanal mixture was heated to 180°C, 3,5-dimethyl-2-ethylpyridine, 3,5-di-methyl-4-ethylpyridine, and 3,5-dimethylpyridine formed. Glycine-propanal mixtnres, also heated to 180°C, gave 2,5-dimethylpyridine and 3,4-dimethylpyridine. This is an example of a nonpyrolytic method of forming pyridines. As small-chain aldehydes reqnired for this reaction are abundant in smoke, this is a feasible ronte to pyridines. 

The complex of 2,6-bis[l-(4-amino-l,2,3,6-tetrahydro-l,3-dimethyl-2,6-dioxop)uimidin-5-yl)imino]ethylpyridine with cadmium(II) of composition CdL2 (05JBI924) reveals antitumor activity. A great number of hetarylazomethine complexes show remarkable antibacterial activity... 

Pyridines and pyrazines, such as 2-ethylpyridine, 2,3,5-trimethyl pyridine, 2-ethyl-3,5-dimethyl pyridine, 2,3-dimethylpyrazine and 2,5-dimethylpyrazine, are the most prominent classes of odorous compounds identified as being responsible for the odour of a cigar smoker s breath. They may be generated during cigar pyrrolysis by cleavage of nicotine or by Maillard reaction. 

Chemical shifts reported in ppm relative to SnMe4 as an external standard. Data quoted at ambient temperature. = l-(2-pyridylazo)-2-naphtholale. = 3-(2-pyridyl)-2-thienyl. = 2-(2-oxo-A-pyrrolidinyl)ethyl. = 2-ethylpyridine. = 2-(4,4-dimethyl-2-oxazolinyl)-3-thienyl. L = 4-ethylpyridine. 

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