Piperidine hydrochloride

In many instances the degree of solubility of the acidic reaction products determines whether autocatalysis occurs. Thus, the reaction of 5-chloroacridine with piperidine is autocatalytic in ethanol but not in toluene where most of the piperidine hydrochloride formed precipitates. ... 

Aminonitrile formation on 125 with potassium cyanide and piperidine hydrochloride affords the derivative, 135. Hydrolysis as above gives the corresponding amide (136). Debenzylation is accomplished by catalytic reduction. Alkylation of the secondary amine with the side chain (96) used in the preparation of diphenoxylate affords pirintramide (138) This compound, interest-... 

Cl Preparation of 1 -Methyt-4-(5-Dibenzo[a,e] Cydoheptatrienytidenej-Piperidine Hydrochloride 1-Methyl-4-(5-hydroxy-5-dibenzo[a,e] cycloheptatrienyO-piperidine (3.05 g,... 

A sample of 4 parts is recrystallized from a boiling mixture of 80 parts isopropanol, 40 parts methanol and 500 parts water. The whole is filtered and after cooling the filtrate overnight at -20°C, 1-benzyl4-(2,6-dioxo-3-pheny -3-piperidyl)-piperidine hydrochloride is obtained, melting point 299°C to 301,5°C, as a white amorphous powder. 

A mixture of 17.6 grams of p-n-butoxyacetophenone, 12.1 grams of piperidine hydrochloride, 4.5 grams paraformaldehyde, 0.25 cc concentrated hydrochloric acid, 52.5 cc nitro-ethane, 7.5 cc of 95% ethanol, and 15 cc of toluene was boiled under reflux for one hour, removing water formed in the reaction by means of a condensate trap. The mixture was then cooled. The crystals which formed were collected by filtration, washed with anhydrous ether and recrystallized from methyl ethyl ketone. The crystals thus obtained, which melted at 174°-175°C, were shown by analysis to be 4-n-butoxy-beta-piperidinopropiophen-one hydrochloride. 

Chemical Name 1-methyl-3-(9H-thioxanthen-9-yl-methyl)piperidine hydrochloride Common Name —... 

Piperidine hydrochloride 1 -SenzyI-4-piperidone 7-Chloro-4-fluorobutyrophenone... 

To a stirred solution of 130.4 parts of potassium cyanide and 243.2 parts of piperidine hydrochloride in a mixture of 800 parts of water and 320 parts of ethanol is added portionwise 378 parts of 1 -benzyl-4-piperidone. After about one hour a solid starts to precipitate. Stirring is continued for 24 hours. The reaction mixture is filtered and the solid is recrystallized from 1,200 parts of diisopropyl ether. On cooling to room temperature a first crop of 1-benzyi-4-cyano-4-piperidinopiperidine melting at about 104°C to 106°C is obtained. 8y concentrating and further cooling of the mother liquor a second crop of the above compound is obtained. 

This compound was boiled with 12 g of dry piperidine in 120 ml of absolute benzene for 12 hours under reflux, a total of 6 g of piperidine hydrochloride being separated out. This was filtered off and the benzene solution was concentrated by evaporation. The residue was taken up in a little chloroform and the solution was applied to a dry aluminum oxide column (according to Brockmann) it was thereafter extracted with chloroform. After concentrating the solution by evaporation, an oil was obtained, which was taken up in absolute diethylether. Introduction of dry HCI gas into the cooled solution gave a precipitate which was dissolved and allowed to crystallize from isopropanol/ether. MP 193° to 199°C. 

Chemical Neme 4-(9,10-Dihydro-4H-benzo[4 61 cyclohepta [1,2-b]thien-4-yIidene-1 -methyl-piperidine hydrochloride... 

CN (3S-rra/i )-(-) 3-[(l,3 benzodioxol-5-yloxy)methyl]-4 (4-fluorophenyI)piperidine hydrochloride... 

CSH4F2 372-18-9) see Fluconazole Risperidone 2,4 -difluorobenzophenone (C13HJF2O 342-25-6) see Flutrimazole 4-(2,4-difluorobenzoyl)piperidine hydrochloride (C12H14CIF2NO 106266-04-0) see Risperidone 6a,9-difIuoro-2-chloro-16(i-methyl-ljp,17-dihydroxy-21-acetoxypregna-1,4-diene-3,20-dione (C24H29CIF2O4 23961-22-0) see Halometasone... 

Subsequently, the scope of the reaction was extended to N-nucleophiles 82. Because the inherent basicity of the substitution products 83 imposed some problems concerning catalyst decomposition, the addition of catalytic amoimts of piperidine hydrochloride (pip-HCl) proved to be necessary. Under optimized reaction conditions different aromatic amines 82 were allylated with almost exclusive regioselectivites in favor of the ipso substitution products 83 (eq. 1 in Scheme 20) [64]. 

Ce(ROH)Cl3 X R = CH3 or C2Hs X= Pyridinehydrochloride 3-methylpyridinehydrochlo-ride piperidine hydrochloride or isoquinolinehydrochloride 121, 122... 

In the hydrogenation of 2- and 2,6-substituted quinoxalines, the presence of piperidine hydrochloride as additive full conversions and enantioselectivities of up to 96% were obtained [40]. These results represent the highest selectivity reached for this class of heterocyclic compounds reported as yet [22, 42, 43]. 

Perhydropyrido[l,2-h][l,2]thiazine-l,1-dioxide was prepared in 70% yield by the cyclization of 2-(3-chlorosulfonylpropyl)piperidine hydrochloride, obtained from 5-[3-(2-piperidyl)propyl]isothiourea dihydrochlorides with chlorine gas, on heating in toluene (62AP615). 

Pyridine 1-oxide either alone or as a mixture with pyridine has occasionally been used as starting material for the preparation of 2,2 -bipyridine, using palladium or platinum catalysts. Sometimes 2,2 6, 2"-terpyridine is formed as well. " The method has been extended to the preparation of substituted 2,2 -bipyridines." Piperidine hydrochloride can be used... 

The mixture is stirred for 2 h at room temperature. Then the reflux condenser is removed and the flask is fitted with a frit (medium porosity, 5-6 cm diameter). The mixture is filtered to remove the piperidine hydrochloride, the solid is washed twice with 50-mL portions of diethyl ether and the filtrate, which is dark brownish red, is evaporated to dryness under vacuum to get a dark red solid. 

FIGURE 13 Chromatograms of l-benzyl-4-[(5,6-dimethoxy-l-indanon)-2-yl] methyl-piperidine hydrochloride enantiomers on (a) avidin-DCS and (b) avidin CSPs using ammonium acetate (0.1 M, pH 5.0) with (a) 5% and (b) 1% acetonitrile as the mobile phases. (From Ref. 71.)... 

Donepezil was prepared by reacting of 5,6-dimethy-l-indanone 1 with l-benzyl-4-formylpiperidine 2 in the presence of strong base such as lithium diispopylamide to give l-benzyl-4-[(5,6-dimethoxy-l-inda-non)-2-ylidenyl]methyl piperidine hydrochloride 3 [12]. The next step is catalytic hydrogenation with 10% palladium on charcoal in THF. The product was purified by column chromatography. The process is illustrated in Scheme 3.2. 

H. Sugimoto, Y. Iimura, Y. Yamanishi, K. Yamatsu, Synthesis and antiacetylcholinesterase activity of l-benzyl-4-[(5,6-dimethoxy-l-indanon-2-yl)methyl]piperidine hydrochloride (E2020) and related compounds, Bioorg. Med. Chem. Lett. 2 (1992) 871-876. 

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