Rearrangement of α-Aminoketones During Clemmensen Reduction. XI. The Reduction of Atom-bridged Bicyclic α-Aminoketones^1,2

Preparation of novel azabicyclic amines and α7 nicotinic acetylcholine receptor activity of derived aryl amides

“…Slow addition of a solution of the piperidine trifluoroacetate salt to a dilute solution of Hunig's base in refluxing acetonitrile afforded azabicyclic ketone 13 in good yield. While ketone 13 has been prepared previously via Dieckmann condensation of diester 14, the product was isolated in less than 1% yield [20]. Conversion of ketone 13 into the corresponding oxime followed by dissolving metal reduction and treatment with para-toluenesulfonic acid afforded diamine (±)-15 in good yield.…”

“…Elution with chloroform-methanolammonium hydroxide (95:4.5:0.5) gave 1.59 g (81%) of 13 as a clear solid: mp 129-131 °C (lit. [20] To a stirred solution of the above mixture of oximes (1.67 g, 10.8 mmol) in n-propanol (150 mL) at reflux temperature was added sodium metal (3.7 g, 162 mmol) in small portions over 30 minutes. Heating at reflux was continued for 2 h. The solution was cooled to RT and diluted with ethyl acetate and brine.…”

Indoles from o-nitrostyrenes. Synthesis and reactions of 2-indolyl 4-piperidylmethyl ketone

“…The oil crystallized to give a white solid, mp 63-65°, when stirred with Anal. Caled for C15H19N02: C, 73.44; , 7.81. Found: C, 73.32; H, 7.93. l-(l-Benzoyl-4-piperidyl)-4-(2-nitrophenyl)-3-buten-2-one (6). -l-Benzoyl-4-piperidyl-2-propanone (9.8 g, 40 mmoles) and 0-nitrobenzaldehyde (15.1 g, 0.100 mole) were dissolved in ether (60 ml) at 0°and treated with 12 ml of a solution prepared from 3 ml of 10% sodium hydroxide and 25 ml of ethanol.…”

“…A. From 1-(l-Benzoyl-4-piperidyl)-4-(2-nitrophenyl)-3-buten-2-one (6).-The nitrostyrene 6 (10.6 g, 28 mmoles) was dissolved in freshly distilled triethyl phosphite (100 ml), and this solution was added dropwise during 1 hr to 175 ml of triethyl phosphite maintained in an oil bath at 125-130°. When the addition was complete, the solution temperature was gradually raised to 145°over 45 min.…”

“…The methyl ketone required for the synthesis of 1, 4-piperidyl-2-propanone (3), has been prepared from ethyl 4-piperidylacetate in low yield. 6 In this work it was prepared by catalytic hydrogenation of 4-pyridyl-2-propanone7 (2) and isolated as the benzoyl derivative 4 (Scheme I). The ketone 4 reacted readily with o-nitrobenzaldehyde (5) to give a mixture which, when refluxed in benzene containing p-toluenesulfonic acid, gave the crude nitrostyrene 6.…”