2- pyridine preparation

Table 27 Pyrazolo[3,4-b]pyridines prepared by oxidative cyclization (Equation 51) <1997SC2217>...

Narrow-distribution bisphenol-A oligomer bischloroformates can be isolated by fractional precipitation of pyridine-prepared oligomers. Oligomer XII was separated into three fractions by adding hexane to a... 

TABLE X. Pyridines Prepared by Hydrogen Halide Cyclization of 1,3-Dinitriles... 

The iV-alkylation was considered to occur by the reaction of the carbonyl compounds, formed by the dehydrogenation of alcohols over the catalyst, with the hydrogenation products of pyridine,25 as suggested by Schwoegler and Adkins, who obtained good yields of /V-alkylpiperidines by the reaction of piperidine with alcohols.26 Maruoka et al. obtained a higher maximal yield of the iV-ethylated product in ethanol over Raney Co than over Raney Ni in the hydrogenation of 5-ethyl-2-methylpyridine (eq. 12.16),23 an alkylated pyridine prepared industrially by the reaction of acetaldehyde with ammonia. 

Table 8 Examples of 3-Alkyl- and 3-Aryl-[l,2,4]triazolo[4,3-a]pyridines Prepared from 2-Hydrazinopyridines and Carboxylic Acids, Anhydrides, Esters or Ortho Esters <66JOC25i, 78JHC439.7OJHC703,70JHC1019)...

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