JV-Methylpiperidine

Liebbrandt have prepared arecaidine by bromination of methyl jV-methylpiperidine-3-carboxyIate, scission of hydrogen bromide from the resulting bromo-compound (VI) and hydrolysis of the resulting arecoline, but Preobrachenski and Fischer were unable to confirm this observation. 

The complex (269) is hexameric in the solid state and in solution, and the same structure presumably occurs in the complexes Ni(SR)2 obtained from reaction (197). In the cyclic hexamer the six nickel atoms form a regular hexagon with twelve symmetrically bridging SEt-groups which are situated above and below the plane of the nickel atoms.1944 A corresponding cyclic tetramer has been obtained with jV-methylpiperidine-4-thiolate anion, SCsHsNMeJ.1946 Also in the complex [Ni(SC5H9NMe)2]4 (270) the nickel atoms lie in a plane. 

Addition of piperidine to acetylenic esters is, surprisingly, asserted to be independent of both solvent and base.289 JV-Methylpiperidine adds to MP in highly aqueous media giving the betaine 64.270 Winterfeldt and Krohn271 added A-hydroxypiperidine to DM AD and obtained the single adduct 65. 

Anabasine (3-(2-piperidinyl)-pyridine) from Mcotiana and Duboisia species (Solanaceae) is an nACh-R agonist used to discourage tobacco smoking as is the JV-methylated tricyclic piperidine (—)-lobeline from Lobelia species (Campanulaceae). Lobeline-related compounds from Lobelia species include the bicyclic jV methyltetrahydropyridines isolobinine and lobinine and the tricyclic jV-methylpiperidines lobelanine and lobelanidine. Anabasine-related compounds include anatabine (2-(3-pyridyl)-l,2,3,6-tetrahydropyridine) from M tabacum and (+)-ammodendrine (jV-acetyltetrahydroanabasine) from Ammodendron and Sophora species (Fabaceae). 

Use of the aldehyde 75 avoids condensation directly onto the pyrazine ring. Reaction of this compound with the activated acetonitriles 76 at room temperature in the presence of JV-methylpiperidine gave the condensation products 77, which on treatment with alkali gave the 6-amino compound 78. It was also found that pteridine (79) gave pyrido[2,3-hjpyrazines directly on treatment with the acetonitriles. ... 

Pyrolysis of jV-methylpiperidine oxide (33) results in no reaction however, on increasing the ring size, seven- and eight-membered cyclic amines undergo ring opening readily. For example, derivatives 34 and 35 form the ring-opened products 36 and 37 in 53% and 79%, respectively. 4... 

Mitsudo et al. [32] found that hydroquinones can be obtained by the reaction of internal alkynes with norbornene and CO using JV-methylpiperidine as a solvent in the presence of Ru3(CO)i2 (Eq. 16). The reaction is proposed to proceed via the maleoyl ruthenium complex 15, which is generated from an alkyne, two molecules of CO, and ruthenium. Norbornene is inserted into this complex to give the quinone, which undergoes reduction to the final product under the re-... 

Glutarimides disubstituted in a or positions were hydrogenolyzed by sodium borohydride in aqueous methanol mainly to disubstituted y-hydroxy-valeramides [7725], but 7V-methylglutarimide was reduced electrolytically in sulfuric acid to a mixture of JV-methylpiperidone (15-68%) and 7V-methylpi-peridine (7-62%) [7727], and by lithium aluminum hydride in ether to N-methylpiperidine in 85% yield [7725]. 

These results refer to 1,2,2,6-tetramethyl piperidine which has a greater JV-Me preference than N-methylpiperidine. 

The condensation of the iV-methylpiperidine (270) with cyanoacetamide gives the hexahydro-2,7-naphthyridine (271) (67AK(26)489), and the reaction between a-oxoketene S,S- acetals (272) and JV-methylcyanoacetamide gives the 2,7-naphthyridine derivatives (273) (78JCS(P1)554). 

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