Showing papers on "Piperidine published in 1977"

Absolute configuration of glycerol derivatives. 4. Synthesis and pharmacological activity of chiral 2-alkylaminomethylbenzodioxans, competitive alpha-adrenergic antagonists.

Abstract: The optical isomers of alpha-adrenergic receptor antagonists prosympal (2), piperoxan (3), and dibozane (4) were prepared by methods establishing the absolute configuration of each. (2S)-3(2'-Hydroxyphenoxy)-1,2-propanediol ditosylate (10) was prepared from (2R)-3-tosyloxy-1,2-propanediol acetonide (6). Intramolecular displacement afforded (2S)-tosyloxymethylbenzodioxan [(2R)-11]. Reaction of (2R)-11 with the appropriate amine (diethylamine, piperidine, or piperazine) afforded the 2S isomers of 2, 3, and 12, respectively. Reaction of (2S)-12 with (2R)-11 afforded the SS isomer of 4. Reaction of (2S)-3-benzyloxy-1,2-propanediol ditosylate (14) with catechol (NaOMe) afforded (2R)-benzyloxymethylbenzodioxan (15). Subjecting 15 to hydrogenolysis, tosylation, and displacement with the appropriate amine afforded 2R isomers of 2, 3, and 12. Reaction of (2R)-12 with (2S)-11 afforded (RR)-4. Reaction of (2R)-12 with (2R)-11 afforded meso-4. The S isomers were more effective antagonists to the alpha-adrenergic response of methoxamine-induced contraction of rabbit aortic strips by twofold in 2 and 18-19-fold in 3 and 4. meso-4 was as effective as the SS isomer of 4. The results are interpreted in terms of a similar conformational distribution of aminoalkyl, oxygen, and aromatic functional groups of the (S)-benzodioxans and (R)-epinephrine.

Derivatives of 4-aminopiperidine as stabilizers for polymers

Abstract: Derivatives of sterically hindered 4-aminopiperidines are effective as light-stabilizers for organic polymers, especially for polyolefins. The piperidine ring is substituted with at least five alkyl groups, preferably methyl and ethyl groups. The 4-amino group is substituted with mono- or divalent acyl groups. The nitrogen in 1-position may also be substituted with a monovalent organic substituent. The compounds can be synthesized starting from higher homologs of acetone in sequence of several reaction steps.

The Synthesis and Properties of Diacyl Selenides

Abstract: Diacyl selenides were synthesized in good yields by the deselenization of diacyl diselenides, which have conveniently been prepared from acyl chlorides and sodium hydroselenide. The reaction of dibenzoyl selenide with piperidine at 0 °C formed a fairly stable piperidinium salt. The methanolysis of distearoyl selenide gave selenostearic acid as an unstable intermediate.

Permanently stabilized polymers produced by after-treatment with piperidine compounds

Abstract: This invention relates to permanently stabilized polymers containing substituted piperidine derivatives chemically attached to the polymer molecule through O- or N-atoms. Compounds based on 2,2,6,6-tetraalkyl piperidines have now been found which, on the one hand, have a very high stabilizing activity and, on the other hand, contain one or more reactive groups through which they are able to react with the polymers to be stabilized. Stabilized polymers, preferably polyurethane elastomer filaments, films and coatings with a permanent washing-resistant, boiling resistant, acid-resistant, dry-cleaning-resistant and solvent-resistant stabilization based on 2,2,6,6-tetraalkyl piperidine light stabilizers are thus obtained.

Fluorescence labelling of organic acidic compounds with 4-bromomethyl-7-methoxycoumarin (Br-Mmc)

Abstract: 4-Bromomethyl-7-methoxycoumarin (Br-Mmc) is introduced as a fluorescence marker for aromatic and heterocyclic acids. To investigate the applicability of this method on substances of different chemical classes, screening experiments with 110 compounds were carried out using a microrefluxer. Most aromatic and heterocyclic monocarboxylic acids gave Mmc-esters which are fluorescent on thin-layer plates, like the Mmc-esters of fatty acids, which have been previously investigated. Strong acids, alcohols, amides and most amines did not react, whereas certain cyclic amines such as piperidine gave strongly fluorescent derivatives. Mmc-phenyl ethers shows only weak fluorescence. A new standard procedure for quantitative derivatisation was introduced using crown ethers as catalysts. Here the yield was improved, while the reaction time was shortened. Typical Mmc-derivatives were prepared in mmole amounts. Determinations of picomole amounts of aromatic, heterocyclic and aliphatic acids are carried out by in situ fluorescence measurement of their Mmc-derivatives after thin-layer chromatographic separation.

Synthesis and stereospecific antipsychotic activity of (-)-1-cyclopropylmethyl-4-(3-trifluoromethylthio-5H-dibenzo[a,d]cyclohepten-5-ylidene)piperidine.

Abstract: The synthesis and resolution of 3-iodocyproheptadine [(+/-)-5a] and 1-cyclopropylmethyl-4-(3-iodo-5H-dibenzo-[a,d]cyclohepten-5-ylidene)piperidine [(+/-)-5b] are described. The resulting atropisomers undergo reaction with trifluoromethylthiocopper to give optically active products without extensive racemization. In this manner, optically pure (+)- and (-)-3-trifluoromethylthiocyproheptadine [(+)-6a and (-)-6a, respectively] and (+)- and (-)-1-cyclopropylmethyl-4-(3-trifluoromethylthio-5H-dibenzo[a,d]cyclohepten-5-ylidene)piperidine [(+)-6b and (-)-6b, respectively] have been prepared. The influence of a chiral europium shift reagent on the proton and fluorine resonance signals as a diagnostic tool for the determination of the optical purities of these atropisomers is discussed. The four compounds, (+)-6a, (-)-6a, (+)-6b, and (-)-6b, were studied in squirrel monkeys for their ability to block conditioned avoidance responding. All of the antiavoidance activity was found to reside solely in the levorotatory compounds (-)-6a and (-)-6b. Further comparison of the enantiomers (-)-6b and (+)-6b showed that the ability to antagonize apomorphine-induced stereotyped behavior is confined to the levorotatory isomer (-)-6b while weak central anticholinergic activity resides solely in the dextrorotatory isomer (+)-6b. Neither (-)-6b has significant peripheral anticholinergic activity.

Isolation of enammonium salt and its rearrangement to the corresponding iminium salt.

Abstract: Enammonium salt of 2-methyl-1-(β-methylstyryl)piperidine (1) was isolated for the first time and characterized. The enammonium salt, 2-methyl-1-(β-methylstyryl)piperidinium chloride (2), was found to change easily to the corresponding iminium salt, 2-methyl-1-(2-phenylpropylidene)piperidinium chloride (3), at room temperature. The structure of the salts derived from 1-(β-methylstyryl)piperidine (4), 2-methyl-1-(β-methyl-styryl)pyrrolidine (5), 1-(β-methylstyryl)pyrrolidine (6), 1-(2-methyl-1-propenyl)pyrrolidine (7), and 2-methyl-1-(2-methyl-1-propenyl)piperidine (8) were also examined.

Asymmetric synthesis of piperidine derivatives: an application to synthesis of (s)-(−)-sedamine and (s)-(−)-allosedamine

Abstract: (S)-(+)-2-oxo-6-piperidineacetic acid was synthesized by a novel route involving an asymmetric cyclization process. Its absolute configuration was determined by converting it to (S)-(−)-sedamine and (S)-(−)-allosedamine, piperidine alkaloids.

Synthetic studies in the piperidine alkaloid field. Part 1. The 2-azabicyclo[2.2.2]octan-5-one approach to prosopine

Abstract: An approach to the synthesis of the Prosopis alkaloids utilising the Baeyer–Villiger reaction of methyl 2-benzyloxycarbonyl-5-oxo-2-azabicyclo[2.2.2]octane-3-carboxylate (6; R = CO2Me) is described. The boron trifluoride–ether catalysed cycloaddition to cyclohexadiene of methyl 2-(benzyloxycarbonylimino)acetate (8; R = CO2 Me), generated in situ from methyl N-benzyloxycarbonyl-2-methoxyglycinate, gave a mixture of bicyclic adducts (9) and (10). Oxymercuriation of (9) gave the alcohol (11; R = H), and subsequent oxidation gave the ketone (6; R = CO2Me). Baeyer–Villiger oxidations of (6; R = CO2Me or CH2·O2CPh) gave the lactones (14) and (15), respectively, and none of the desired lactone (7).

Modified polyurethanes with increased light stability

Abstract: The incorporation of sterically hindered piperidine derivatives into polyurethanes protects this polymer material against light degradation. Usable for the incorporation are piperidine derivatives which are at least difunctional towards isocyanates and contain the structure ##STR1## wherein R is hydrogen or alkyl having 1 to 5 carbon atoms.

Method of producing the hydrochloride of N-methyl piperidine-2-carboxylic acid-2,6-xylidide

Abstract: Method for producing the hydrochloride of N-methyl piperidine-2-carboxylic acid-2,6-xylidide which include hydrogenating picolinic acid-2,6-xylidide in the pyridine ring in the presence of HCl to the hydrochloride of piperidine carboxylic acid xylidide followed by catalytic reductive methylation using formaldehyde.

Preparation of piperidine

Abstract: PURPOSE:High purity piperidine is prepared in high yield by the hydrogenation of pyridine in the presence of the ruthenium catalyst treated under specific conditions.

Studies on the Syntheses of Heterocyclic Compounds. DCXCII. A Novel Synthetic Route to Phthalideisoquinoline and Spirobenzylisoquinoline Type Alkaloids

Abstract: Permanganate oxidation of 12-chloro-5, 6, 7, 7a-tetrahydro-2, 3, 9, 10-tetramethoxy-7-methylindeno [2, 1-α] [3] benzazepine (5) in the presence of piperidine gave the diketospirobenzylisoquinoline (11) and the lactone (15), the latter of which was converted into erythro-and threo-phthalideisoquinoline (16 and 17). 2, 3-Dihydro-7, 8-dimethoxy-5-(2, 3-dimethoxybenzoyl)-3-methyl-1H-3-benzazepine (4) was prepared from N-β-(3, 4-dimethoxyphenethyl)-2, 3-dimethoxyphenylacetamide (26) in four steps.

Process for preparing 2-(2,2-dicyclohexylethyl)piperidine

Abstract: 2-(2,2-Dicyclohexylethyl)piperidine is prepared via the catalytic hydrogenation of 2-(2,2-diphenylethenyl)pyridine in a single step. High yields are obtained using a rhodium supported catalyst.

Piperidine containing cyanuric acid derivatives

Abstract: New cyanuric acid derivatives containing at least one hindered phenolic moiety and at least one hindered amine moiety are effectful light stabilizers and antioxidants for polymeric materials.

Process for preparing 1-phenyl-3-aminopyrazoles

Abstract: 1-PHENYL-3-AMINO-2-PYRAZOLINES ARE CATALYTICALLY OXIDIZED TO 1-PHENYL-3-AMINOPYRAZOLES, USING OXYGEN AND/OR AIR AS THE OXIDIZING AGENT AND IN THE PRESENCE OF COPPER SALTS, OPTIONALLY ASSOCIATED WITH METALLIC COPPER AND/OR AN AROMATIC, HETEROCYCLIC ORGANIC BASE SELECTED FROM N-dialkyl anilines, pyridines, piperidine, and ethanolamine, or equivalents thereof, in an inert reaction medium and at a temperature of from about 20° C. to about 40° C.

Piperazine and piperidine derivatives

Abstract: OF THE DISCLOSURE Novel compounds are disclosed of the formula: (I) and the pharmaceutically acceptable acid addition salts thereof, wherein: Ar1 and Ar2 are each independently selected from the group consisting of phenyl, substituted phenyl and pyridinyl, wherein said substituted phenyl is phenyl having from 1 to 2 substituents independently selected from the group consisting of halo, lower alkyl, lower alkyloxy trifluoromethyl and nitro; m is an integer zero or 1; A is a member selected from the group consisting of and , provided that when said A is then said m is zero and when said A is then said m is 1; n is an integer of from 2 to 6 inclusive, provided that when CnH2n represents a branched alkylene chain, then at least 2 carbon atoms are present in the linear portion of the chain linking B with the piperidine or piperazine nitrogen atom; and B is a member selected from the group consisting of: a) a radical having the formula wherein: R1 and R2 are each independently selected from the group consisting of hydrogen, halo, lower alkyl and trifluoromethyl; and Y is a member selected from the group consisting of oxygen, sulfur and a substituted nitrogen of the formula , wherein said L is a member selected from the group consisting of hydrogen, lower alkyl, lower alkylcarbonyl, lower alkyloxycarbonyl-lower alkyl, carboxy-lower alkyl, phenyl, phenylmethyl, lower alkylaminocarbonyl, hydroxy-methyl, and lower alkenyl; and b) a radical having the formula wherein: R1 and R2 are each independently selected from the group consisting of hydrogen, halo, lower alkyl and trifluoromethyl; and M is a member selected from the group consisting of hydrogen, lower alkyl, phenyl, phenylmethyl, mercapto, lower alkylthio, amino, lower alkylcarbonylamino, lower alkyloxycarbonylamino, and cycloalkyl having from 3 to 6 carbon atoms. Theses novel 1-substituted 4-(diarylmethyl)piperazine and 4-(diarylmethoxy) piperidine derivatives having anti-anaphylactic and antihistaminic properties.