Tetrahydropyrido azepines

Oxidation of methyl l-oxo-l,4,4a,5-tetrahydropyrido[l,2-a][l,4]benzodi-azepine-2-carboxylate (338) with activated manganese dioxide in boiling toluene for 20 min afforded methyl l-oxo-l//-pyrido[l,2-a]quinazoline-2-carboxylate (340) as a by-product and methyl l-oxo-l,5-dihydropyrido[l,2-a][l,4]benzodiazepine-2-carboxylate (339) (87JHC683). 

Keywords A-84543 A-85380 ABT-089 ABT-418 ABT-594 Aminoethoxypyridines Anabaseine Anabasine Chloronicotine, 6- Cotinine Cytisine Dihydro-P-erythroidine DMXB Epibatidine GTS-21 Isonicotine Lobelanidine Lobelanine Lobeline Metanicotine Myosmine Nicotine Nicotinoids Nornicotine SIB-1508Y SIB-1553A SIB-1765F Tetrahydropyrido[3,4-rf]azepines... 

Scheme 6 A Beckmann ring expansion approach to tetrahydropyrido[3,2-b]azepin-...

A series of tetrahydropyrido[3,2-l ]azepin-6-ones with a trifluoromethyl group was prepared to study their ADME (absorption, distribution, metabolism, and excretion) profile (14ARK139). The pyridine ring was prepared by a traditional condensation followed by the formation of an oxime (Scheme 6). The key step includes a Beckmann ring expansion of this oxime. 

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