1-Methyl-piperidine buffer

Figure 8-71. Effect of wpH 11 buffer type on bidentate-C18P columns, 15 x 0.46 cm. Mobile phase 55% acetonitrile 45% 0.05M buffer (1-methyl-piperidine bnffer was adjusted to pH 11 with HCl and dipotassium monohydrogen phosphate bnffer was adjusted to SpH 11 with NaOH). Flow rate, l.OmL/min, temperature, 23°C UV, 215 nm. (Reprinted from reference 43, with permission.)...

An example is shown in Figure 8-71, where the column stability was evaluated with two different buffers, phosphate buffer ("pFI 11) and 1-methyl piperidine (wpH 11) [43]. Plots of H (plate height) or N versus number of column volumes can be generated. Remember that H is inversely proportional to the efficiency ... 

An aqueous solution of the obtained N-[3-chloro-3-(p-tolyl)propyl]piperidine hydrochloride was hydrogenated at 3 atmospheres in the presence of buffered palladium-on-charcoal catalyst. l-Piperidino-2-methyl-3-(p-tolyl)-3-propanone was purified by distilling the base (boiling point 106-107°C/1 mm) and reconverting to the hydrochloride, melting point 216-217°C. 

They initially discovered several synthetically efficient routes to obtain the hexahydro-l,5-methanoazocino[3,4-f)]indole scaffold. For example, they found that treatment of the pyridine 222 with methyl iodide furnished the pyridinium salt 223, which could be hydrogenated using platinum oxide in ethanol to yield the piperidine 224 (Scheme 26). Oxidative cycHzation was then employed with mercury(II) acetate in a buffered aqueous medium to form iminium ion 225, which underwent subsequent cycHzation at the 2-position of the indole to furnish tetrahydrocarbazole 226. ... 

The revised structure (4) has been determined for physoperuvine the free base is a mixture of bicyciic hydroxy-amine and monocyclic keto-amine tautomers. X-Ray diffraction methods have been used to characterise the unexpected product (5) from addition of nitrosobenzene to pyran-2-thione. the product (6) (from anchimerically assisted oxidative cyciisation of 5-amino-1-thiacyclooctane using iodine in buffered methanol). the exo- and endo-1-methylindene ozonides (7), and the ozonide (8). X-Ray studies confirm that the piperidine ring in 3-thia-7-aza-6,8-diphenylbicyclo[3.3. llnonan-9-ol is boat-shaped and that 2, 6-dinitrato-9-thiabicyclo(3. 3. l)nonane-9. 9-dioxide has a twin-chair conformation. ndo-3-methyl-exo-3-hydroxy-3-silabicyclo(3.2. Itoctane is... 

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