Showing papers on "Piperidine published in 1987"

The metabolism of roxatidine acetate hydrochloride. Liberation of deuterium from the piperidine ring during hydroxylation

Abstract: The metabolism of roxatidine acetate hydrochloride (RA), a new histamine-2 receptor antagonist, was studied by GC/MS in rats and dogs in vivo. The co-administration of 14C-RA and RA-d10 labeled with deuterium in the piperidine ring expedited the isolation and identification of 15 urinary metabolites. The major metabolites in both animals were M-1, M-8, M-10, and M-11; M-4 could be found only in the rat. The aromatic and piperidine ring-hydroxylated metabolites were found in small amounts in both species. Following the administration of RA-d10 to rats and dogs, oxygenated metabolites on the piperidine ring, such as M-3 and M-4, were isolated and their analysis indicated the unexpected loss of three or four deuterium atoms from the ring. Also, first and second isotope effects were observed on the conversion rate in vivo and retention time in HPLC, respectively.

Ruthenium-catalyzed synthesis of vinyl carbamates from carbon dioxide, acetylene, and secondary amines

Abstract: Les amines secondaires etudiees sont pyrrolidine, piperidine, morpholine et diethylamine; obtention egalement de petites quantites de N,N-dialkyl O-[methylene-1 allyl] carbamates

Palladium-catalysed cross double carbonylation of amines and alcohols: synthesis of oxamates

Abstract: Cross double carbonylation of amines and alcohols in the presence of PdCl2(MeCN)2/Cul catalyst under CO and O2 at room temperature gives oxamates efficiently.

N-aralkyl piperidine methanol derivatives and the uses thereof

Abstract: This invention relates to a new class of compounds having important biochemical and pharmacological properties. More particularly, this invention relates to N-aralkyl piperidinemethanol derivatives which are potent and selective inhibitors of the binding of serotonin at the 5HT2 receptor site, and to the processes for their preparation and use.

Piperidine compounds and their preparation and use

Abstract: Piperidine compounds having the formula ##STR1## wherein R3 is 3,4-methylenedioxyphenyl, phenyl, or naphthyl which are optionally substituted with one or more halogen, C1-6 -alkoxy, or phenoxy, cyano, mono or poly halogenated C1-6 -alkyl, C2-6 -alkenyl, C1-6 -alkyl, or C3-5 -alkylene, R1 is straight or branched C1-8 -alkyl substituted with piperidinyl morpholinyl thiomorpholinyl dioxolanyl or tetrahydrofuranyl, which heterocyclic radical is unsubstituted or C1-6 -alkyl substituted, X is hydrogen, halogen, trifluoromethyl, hydroxy, cyano, or C1-8 -alkoxy, Y is O or S; and pharmaceutically-acceptable acid addition salts thereof. The compounds are useful in the treatment of anoxia, migraine, ischemia, and epilepsy.

Enzymes in organic synthesis. 40. Evaluation of the enantioselectivity of the pig liver esterase catalyzed hydrolyses of racemic piperidine carboxylic acid esters

Abstract: Pig liver esterase (PLE) catalyzed hydrolysis of racemic piperidine esters proceeds enantioselectively to give product acids and recovered esters in 0–47% enantiomeric excess.

Certain heterocyclic substituted diphosphonate compounds pharmaceutical compositions, and methods of treating abnormal calcium and phosphate metabolism

Abstract: The present invention relates to novel heterocycle-substituted diphosphonic acids, and the pharmaceutically-acceptable salts and esters thereof, in which the diphosphonate-substituted carbon atom moiety is attached to a carbon atom in a nitrogen-containing six membered ring heterocycle, preferably a piperidine ring. The heterocycle-substituted diphosphonic acid compounds have the general structure: ##STR1## wherein Z is a nitrogen-containing six membered ring heterocycle moiety selected from piperidinyl, diazinyl and triazinyl; m, n and m+n are from 0 to 10; Q is a covalent bond or a moiety selected from oxygen, sulfur or nitrogen; and R 1 , R 2 , R 3 and R 4 are substituent groups. The present invention further relates to pharmaceutical compositions containing these novel compounds. Finally this invention relates to methods for treating or preventing diseases characterized by abnormal calcium and phosphate metabolism by utilizing a compound or pharmaceutical composition of the present invention.

Rapid, low activation energy, selective, direct reactions of cation radicals with nucleophiles. An experimental test of theory

Abstract: Etude cinetique de la reaction du radical cationique du phenyl-9 anthracene avec des derives de la pyridine

Synthesis of 2,2-Dimethyl-2H-thiochromenes, the Sulfur Analogs of Precocenes

Abstract: Synthese de dimethyl-2,2 thiochromenes par deshydratation des thiochromannols-4 correspondants; ceux-ci sont prepares par addition de Michael de thiophenols et d'acide methyl-3 butene-2oique suivie de cyclisation des acides arylthio-3 methyl-3 butyriques puis de reduction des dimethyl-2,2 thiochromannones-4 formees

Nonacidic nitration of secondary amines

Abstract: Nitration de dimethyl- et diethyl-amines, piperidine, pyrrolidine, morpholine a l'aide de nitrate de [methyl-1 trifluoromethyl-1] ethyle ou de dinitrate de bis-chloromethyl-2,2 propanediol-1,3. Obtention de nitramines et de quelques nitrosamines

Mechanism-based inhibition of cytochrome P-450 by heterocyclic analogues of phencyclidine.

Abstract: Three homologues of 1-(1-phenylcyclohexyl)piperidine (PCP) containing the five-, six-, and seven-membered heterocyclic ring (1-(1-phenylcyclohexyl)pyrrolidine (PCPY), PCP, 1-(1-phenylcyclohexyl)hexamethyleneimine (PCHMI) were preincubated with microsomes from phenobarbital-induced rabbit liver. The microsomes were then diluted, an additional charge of NADPH was added, and N-demethylation of benzphetamine was determined. Preincubation of the microsomes with the analogues lowered P-450-dependent N-demethylation by a process that was NADPH-dependent, reduced CO binding to microsomes, and followed pseudo-first order kinetics. The relative rates of inactivation, PCP greater than or equal to PCPY greater than PCHMI, agreed with the order of inhibition of CO binding to reduced microsomes. This mechanism-based inhibition was not observed with phenylcyclohexylamine, indicating that the substituted nitrogen is necessary. The substituted nitrogen must also be part of a heterocyclic ring since the diethylamino analogue of PCP did not exhibit the same type of inhibition a heterocyclic ring is involved. These trends correlated with the expected relative stabilities of the cyclic form of the carbinolamine suggesting that the inhibitory species was formed from the closed ring isomer.

Benzo[b]thiophene- and benzo[b]furancarboxamide derivatives, pharmaceutical compositions and use

Abstract: Compounds of formula: ##STR1## in which R1 and R2 are each alkyl, cycloalkyl or phenyl, or NR1 R2 =piperidine, Ar is optionally substituted phenyl or thienyl, and X< is one of the following linkages: ##STR2## are useful as anxiolytic, antianginal and immunomodulatory agents. They may be made by reaction of an amine with the corresponding acid chloride.

1,3-Dipolar cycloaddition reactions of nitrilium betaines with aryl thiocyanates and selenocyanates

Abstract: The carbon–nitrogen triple bond of aryl thiocyanates acts as a dipolarophile in 1,3-dipolar cycloadditions. Reaction with nitrile oxides, nitrile sulphides, and benzonitrile N-phenylimide yields, respectively, 5-arylthio-1,2,4-oxadiazoles, -thiadiazoles and -triazoles. Aryl selenocyanates behave similarly forming 5-arylseleno-1,2,4-oxadiazoles and -thiadiazoles from nitrile oxides and sulphides. Divergent pathways are followed, by the reactions of secondary amines such as piperidine with 5-arylthio-1,2,4-oxadiazoles and -thiadiazoles, the former yielding 5-piperidyl-1,2,4-oxadiazoles and the latter dihydro-1,2,4-thiadiazole-5-thiones.

Enhanced luminescent assay.

Abstract: In an assay in which a ligand is labelled by conjugation to a dihydrophthalazinedione (DPD), e.g. luminol or isoluminol, and the conjugated DPD is reacted with an oxidant, e.g. hydrogen peroxide, and an active heme group catalyst, e.g. microperoxidase, the light intensity is enhanced by certain sterically hindered amines defined as saturated bycyclic compounds having a nitrogen atom at one or both bridgehead positions or a piperidine ring compound having four C1-4 alkyl groups at the 2- and 6-positions. 1,4-Diazabicyclo[2.2.2]-octane, known as ''DABCO'' is preferred.

A New Method for Introducing Some Active Methylene or Methine Groups to the 3-Position of Pyrrolidine or Piperidine Skeleton, and Its Application to Preparation of a Key Intermediate for (±)-Eburnamonine Synthesis

Abstract: A new method for introducing a bis(methoxycarbonyl)methyl or 2-oxopropyl group to the 3-position of pyrrolidine or piperidine skeleton has been exploited, and this method could be used in the synthesis of a key intermediate for the (±)-eburnamonine synthesis.