Ethyl 4-piperidinecarboxylate

Ethyl 1-piperazinecarboxylate 1-Ethylpiperidine Ethyl 4-piperidinecarboxylate Ethyl 1-piperidinepropanoate 1-Ethyl-3-piperidinol AI-Ethyl-1-propanamine Ethylpropanedioic acid... 

Ethyl 1-piperazinecarboxylate 1-Ethylpiperidine Ethyl 4-piperidinecarboxylate EBiyll-pipetidineptopanoale... 

The second route was applied to the preparation of the tctrahydropyrido[ 1, Z-d 1,2,4 tria/incdione 142 by reaction of ethyl piperidinecarboxylate 140 with protected hydrazines 139 via intermediate 141 (Scheme 15) <2003SC1011>. 

Chemicei Name 1-[2-(4-aminophenyl)ethyl]-4-phenyl-4-piperidinecarboxylic acid ethyl ester dihydrochloride... 

CN 4-(8-chloro-5,6-dihydro-l lJ/-benzo[5,6]cyclohepta[l,2-fo]pyridin-l l-ylidene)-l-piperidinecarboxylic acid ethyl ester... 

Tetrabutylammonium fluoride Ammonium, tetrabutyl-, fluoride (8) 1-Butanaminium, N,N,N-tributyl-p fluoride (9) (429-41-4) l-Carbethoxy-4-piperidone 1-Piperidinecarboxylic acid, 4-oxo-, ethyl ester (8,9) (29976-53-2)... 

Carbethoxy-4-piperidone 1-Piperidinecarboxylic acid, 4-oxo-, ethyl ester (8,9) (29976-53-2)... 

The kinetics and mechanisms of gas-phase elimination of ethyl 1-piperidinecarboxyl-ate, ethyl pipecolinate, and ethyl 1-methylpipecolinate has been determined in a static reaction system.9 The reactions proved to be homogeneous, unimolecular, and obey a first-order rate law. The first step of decomposition of these esters is the formation of the corresponding carboxylic acids and ethylene. The acid intermediate undergoes a very fast decarboxylation process. The mechanism of these elimination reactions has been suggested on the basis of the kinetic and thermodynamic parameters. 

To a stirred solution of 28.3 g of NG-nitro-N2-(tert-butoxycarbonyl)-L-arginine in 450 ml of dry tetrahydrofuran were added in turn 9.0 g of triethylamine and 12.2 g of isobutyl chloroformate while keeping the temperature at -20°C. After 10 minutes, to this was added 15.2 g of ethyl 4-methyl-2-piperidinecarboxylate and the mixture was stirred for 10 minutes at -20°C. At the end of this period, the reaction mixture was warmed to room temperature. The solvent was evaporated and the residue taken up in 400 ml of ethyl acetate, and washed successively with 200 ml of water, 100 ml of 5% sodium bicarbonate solution, 100 ml of 10% citric acid solution and 200 ml of water. The ethyl acetate solution was dried over anhydrous sodium sulfate. The solution was evaporated to give 31.5 g (75 %) of ethyl l-[NG-nitro-N2-(tert-butoxycarbonyl)-L-arginyl]-4-methyl-2-piperidinecarboxylate in the form of a syrup. 

To a stirred solution of 30 g of ethyl l-[NG-nitro-N2-(tert-butoxycarbonyl)-L-arginyl]-4-methyl-2-piperidinecarboxylate in 50 ml of ethyl acetate was added 80 ml of 10% dry HCI-ethyl acetate at 0°C. After 3 hours, to this solution was added 200 ml of dry ethyl ether to precipitate a viscous oily product. This was filtered and washed with dry ethyl ether to give ethyl l-[NG-nitro-L-arginyl]-4-methyl-2-piperidinecarboxylate hydrochloride as an amorphous solid. 

A solution of 30 g the above product in 100 ml of ethanol and 100 ml of 1 N sodium hydroxide solution was stirred for 24 hrs at room temperature. At the end of this period, the solution was neutralized with 1 N hydrochloric acid and then concentrated to 70 ml. The solution was adjusted to pH=ll with 1 N sodium hydroxide solution, washed three times with 100 ml of ethyl acetate, acidified with 1 N hydrochloric acid and then extracted three times with 100 ml of chloroform. The combined chloroform solution was dried over anhydrous sodium sulfate and evaporated to give 28.0 g (97%) of l-[NG-nitro-N2-(3-methyl-8-quinolinesulfonyl)-L-arginyl]-4-methyl-2-piperidinecarboxylic acid as an amorphous solid. IR (KBr) 3,300, 1,720, 1,630 cm-1. 

Ethyl 4-isothiocyanato-l-piperidinecarboxylate Potassium hydroxide Sodium carbonate... 

A mixture of 54 parts of ethyl 4-isothiocyanato-l-piperidinecarboxylate, 48 parts of N2-(2-furanylmethyl)-2,3-pyridinediamine and 450 parts of tetrahydrofuran was stirred and refluxed overnight. The reaction mixture was evaporated and the residue was crystallized from a mixture of 2-propanone and 2,2 -oxybispropane. The product was filtered off and dried, yielding 76 parts (75%) of ethyl 4-[[[2-[(2-furanylmethyl)amino]-3-pyridinyl]aminothioxomethyl]amino]-l-piperidinecarboxylate melting point 132.7°C. 

A mixture of ethyl 4-[[3-(2-furanylmethyl)-3H-imidazo[4,5-b]pyridin-2-yl]amino]-l-piperidinecarboxylate and of a hydrobromic acid solution 48% in water was stirred and heated for 3 h at about 80°C. The reaction mixture was evaporated and the residue was dried, yielding the 3-(2-furanylmethyl)-N-(4-piperidinyl)-3H-imidazo[4,5-b]pyridin-2-amine dihydrobromide (crystallized from methanol). 

Ethyl 3-(2-ethoxycarbonylethyl)-4-phenlimino-l-piperidinecarboxylate (20) underwent reductive cyclization to ethyl 2-oxo-l-phenyl-l,2,3,4,5,6,7,8-octa-hydro-l,6-naphthyridine-l-carboxylate (21) (NaBH4, dioxane, 20°C, 12h 27%) or its decahydro analog (substrate, THF, HC1 gas [, NaBH3CN/MeOH [ slowly, 20°C, 3.5 h 22%).1104... 

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