3.3- Dimethyl-2-piperidino

Cyclobutan l-Cyan-3,3-dimethyl-2-piperidino- IV/4, 284 Decandisaure 2,9-Dimethyl- -dinitril E18, 815 (In + CO-CN/H2)... 

The heterocyclic alkylphosphocholine derivative octadecyl-(l,l-dimethyl-piperidino-4-yl) phosphate (D-21266 perifosine) was developed and selected for improved gastrointestinal tolerability in animal experiments. A number of phase I studies are presently ongoing in Europe and the United States early evidence... 

The ortho indirect deactivating effect of the two methyl groups in 2,6-dimethyl-4-nitropyridine 1-oxide (163) necessitates a much higher temperature (about 195°, 24 hr) for nucleophilic displacement of the nitro group by chloride (12iV HCl) or bromide ions N HBr) than is required for the same reaction with 4-nitropyridine 1-oxide (110°). With 5-, 6-, or 8-methyl-4-chloroquinolines, Badey observed 2-7-fold decreases in the rate of piperidino-dechlorination relative to that of the des-methyl parent (cf. Tables VII and XI, pp. 276 and 338, respectively). 

Likewise, amine functions on the azepine ring at an unsaturated carbon center behave as enamines and undergo hydrolysis under both acid and alkaline conditions to the benzazepinones.15,64 8084 However, hydrolysis of dimethyl l-acetyl-5-piperidino-l//-l-benz-azepine-3,4-dicarboxylate(18) yields not the benzazepinone but the tautomeric 5-hydroxy derivative 19.13 Presumably, the enol form is stabilized by intramolecular hydrogen bonding. 

Likewise, 6-chloro-2-piperidinoquinoxaline 4-oxide (291) gave dimethyl 8-chloro-4-piperidino-3 a//-isoxazolo [2,3 -a] quinoxaline-2,3 -dicarboxylate (292)... 

In contrast, the same substrate (291) gave trimethyl 8-chloro-4-piperidinopyr-rolo[l,2-fl]quinoxaline-l,2-3-tricarboxylate (293) [Me02CC=CC02Me (2 mol), dioxane, reflux, 6 h 30%]" ° " or dimethyl 8-chloro-4-piperidino-pyrrolo[l,2-fl]quinoxaline-l,3-dicarboxylate (294) [HC=CC02Me (2 mol), dioxane, reflux, 10 h 16%] ° mechanisms are suggested." °... 

Cobalt(III) complexes of formula cis- and trans-[Co(dtc)L4]2+ and [Co(dtc)2L2]+ where dtc = dimethyl-, diethyl- or piperidino-dithiocarbamate were prepared with phosphites P(OMe)3, P(OEt)3 and 4-ethyl-2,6,7-trioxa-l-phophabicyclo[2.2.2]octane as ligands L.1048 Whereas Co—P bonding is found, as defined in the crystal structures of each of the two forms of complexes isolated, a linkage isomer in which the phosphite is O bound was detected for the bis(dithio-carbamate) compounds. 

An amino alcohol was found to accelerate the addition reaction of diethlylzinc to aldehyde [8], and then chiral amino alcohols were proved to be efficient chiral catalysts for asymmetric alkylation by using dialkylzinc reagents [9], Oguni reported a remarkable asymmetric amplification in chiral amino alcohol-promoted alkylation (Scheme 9.4). In the presence of (-)-l-piperidino-3,3-dimethyl-2-butanol (5) of 11% ee, benzaldehyde is alkylated enantioselectively to give (/ )-l-phenylpropanol with 82% ee [10]. Asymmetric amplification was also observed by Noyori using partially resolved (2.S )-3-exo-(dimethylamino)isobomeol (6) [11]. 

The cation radical intermediates formed from the enamines may be trapped by nucleophiles other than the solvent when these nucleophiles are electrochemically less oxidizable than the enamines. Indeed, the cation radical intermediates formed from morpholino-, piperidino-and pyrrolidinoenamines are trapped by carbanions derived from active methylene compounds such as methyl acetoacetate, acetylacetone and dimethyl malonate with moderate yields (equation 2)3. The products are easily transformed to the corresponding a-substituted ketones by hydrolysis with dilute hydrochloric acid. 

Azido-2,2-dimethyl-8-oxo-E16b, 723 (CH - C-N3) lH-Pyrazol 4-Nitro-3(5)-piperidino-E8b, 598 (N02 - NR2) Pyrimidin 5-Ethoxycarbonyl-2-hydrazino-4-methyl- El 6a, 771 (SR - NH-NH2) lH-Tetrazol l-(l-Carboxy-2-methyl-... 

Cyclopropan 1-Cyan-l-piperidino-E17b, 1589 (OR - CN) Heptandisaure 2,6-Dimethyl- ... 

Ammoninm (Piperidino-methyl)-trimethyl- -bromid E16a, 1008 (N-Aminomethylier.) Formamidinium N,N -Dimethyl-N,N -dipropyl-(iodid) E5, 94 (N-Alkylier.) N,N,N, N -Tetraethyl- (methylsulfat) E5, 90 (OR - NR2) Piperidinium l-(Dimethylamino-methyl)-l-methyl- -bromid E16a, 1008 (N-Aminomethylier.)... 

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