- Selective deprotective method using palladium-water soluble catalysts
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Allylcarboxy and Allyloxycarbonyl groups can be removed without affecting dimethylallylcarboxy and cinnamylcarboxy groups in the same molecule. using Pd(O) water soluble catalyst prepared in situ, with diethylamine as allyl scavenger. Homogeneous or biphasic media are suitable: the yields of deprotection are quantitative.
- Lemaire-Audoire,Lemaire-Audoire, Sandrine,Savignac,Savignac, Monique,Blart,Blart, Errol,Pourcelot,Pourcelot, Guy,Genet,Genet, Jean Pierre,Bernard,Bernard, Jean-Marie
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Read Online
- Synthesis method for co-production of N-hydroxyethyl piperazine and N-ethyl piperazine
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The invention discloses a method for co-production of N-hydroxyethyl piperazine and N-ethyl piperazine. The method comprises the following steps: reacting methyl glycolate serving as a process intermediate for preparing ethylene glycol by a coal method with piperazine to generate an intermediate product carbonyl hydroxyethyl piperazine, then in the presence of a hydrogenation catalyst, carrying out hydrogenation reduction and dehydration under certain pressure and temperature conditions to obtain N-hydroxyethyl piperazine, and simultaneously co-producing part of N-hydroxyethyl piperazine. Themethod is simple and convenient, low in cost, high in total yield, good in selectivity, easy in product separation and environment-friendly.
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Paragraph 0008; 0029-0087
(2021/03/11)
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- Synthesis method of N-hydroxyethylpiperazine
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The invention discloses a synthesis method of N-hydroxyethylpiperazine, which comprises the following steps: by using piperazine and hydroxyacetaldehyde as raw materials and carrying out intermolecular dehydration condensation with hydrogen in the presence of a catalyst to generate N-hydroxyethylpiperazine; wherein the catalyst is composed of a Raney skeleton element and other auxiliary elements (at least one of iron, manganese, zinc, chromium, zirconium and cobalt) loaded on the Raney skeleton element. The method is simple in process operation, high in conversion rate, good in selectivity, simple in post-treatment and environment-friendly. Some examples prove that the yield of the method can reach about 90%, so that the method has a good industrial prospect.
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Paragraph 0027-0078
(2020/06/20)
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- Synthesis method of dasatinib intermediate
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The invention discloses a synthesis method of a dasatinib intermediate. The dasatinib intermediate is 1-(2-hydroxyethyl)piperazine; the synthesis method comprises the following step: carrying out one-step temperature control reaction synthesis by utilizing bi(2-chloroethyl)amine and ethanolamine under the action of a acid-bonding agent to obtain the dasatinib intermediate. Compared with a method in the prior art, the synthesis method has the advantages of improved yield, simple steps, convenience for operation and few byproducts. According to the synthesis method, reaction is carried out without the need of adopting a high-pressure reaction kettle; the requirements on production equipment are lower and industrial production is facilitated.
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Page/Page column 3; 4
(2018/07/28)
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- Biocatalytic Access to Piperazines from Diamines and Dicarbonyls
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Given the widespread importance of piperazines as building blocks for the production of pharmaceuticals, an efficient and selective synthesis is highly desirable. Here we show the direct synthesis of piperazines from 1,2-dicarbonyl and 1,2-diamine substrates using the R-selective imine reductase from Myxococcus stipitatus as biocatalyst. Various N- and C-substituted piperazines with high activity and excellent enantioselectivity were obtained under mild reaction conditions reaching up to 8.1 g per liter.
- Borlinghaus, Niels,Gergel, Sebastian,Nestl, Bettina M.
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p. 3727 - 3732
(2018/04/14)
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- METHOD FOR PRODUCING CIS- AND TRANS-ENRICHED MDACH
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A process for preparing trans-enriched MDACH, including: distilling an MDACH starting mixture in the presence of an auxiliary, which is an organic compound having a molar mass of 62 to 500 g/mol, a boiling point at least 5° C. above the boiling point of cis,cis-2,6-diamino-1-methylcyclohexane, and 2 to 4 functional groups, each of which is independently an alcohol group or a primary, secondary or tertiary amino group. The MDACH starting mixture includes 0 to 100% by weight of 2,4-MDACH and 0 to 100% by weight of 2,6-MDACH, based on the total amount of MDACH present in the MDACH starting mixture. The MDACH starting mixture includes both trans and cis isomers. Trans-enriched MDACH includes 0 to 100% by weight of 2,4-MDACH and 0 to 100% by weight of 2,6-MDACH, where the proportion of trans isomers in the mixture is higher than the proportion of trans isomers in the MDACH starting mixture.
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- Preparation method of manidipine hydrochloride
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The invention discloses a preparation method of manidipine hydrochloride and belongs to the technical field of medicine preparation. Piperazine serving as a starting raw material is used for synthesis of N-(2-hydroxyethyl)piperazine, then 1-diphenylmethyl-4-(2-hydroxyethyl)piperazine is synthesized, and 2-(4-diphenylmethyl-1-piperazinyl)ethyl acetoacetic ester is synthesized; 2-(4-diphenylmethyl-1-piperazinyl)ethyl acetoacetic ester, m-nitrobenzaldehyde and methyl 3-aminocrotonate are dissolved in isopropanol, the mixture is subjected to heating reflux, a solvent is removed through steaming, residues are dissolved in trichloromethane, the mixture is dried with anhydrous sodium sulfate and filtered, a solvent of the filtrate is recovered under reduced pressure, residues are mixed with methanol to be completely dissolved, hydrogen chloride is introduced in an ice bath, the solvent is removed through steaming, residues are mixed with methanol, activated carbon is added for decoloration, filtering is performed, filtrate is cooled, and manidipine hydrochloride is obtained. The preparation method of manidipine hydrochloride is simple in process, the yield is high, the cost is low, and the product purity is high.
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Paragraph 0035; 0036; 0044; 0045; 0054; 0055; 0064; 0065
(2017/12/06)
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- 1-(2-hydroxy ethyl) piperazine synthetic method
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The invention discloses a 1-(2-hydroxy ethyl) piperazine synthetic method. The 1-(2-hydroxy ethyl) piperazine synthetic method includes the steps that 2-molindone and 2-chlorohydrin are reacted, and 2-keto-4-(2-hydroxy ethyl)-morpholine is generated; then the 2-keto-4-(2-hydroxy ethyl)-morpholine and ammonia are reacted to generate 1-(2-hydroxy ethyl) piperazine. According to the 1-(2-hydroxy ethyl) piperazine synthetic method, the raw materials are simple and easy to obtain, the reaction yield is high, aftertreatment is easy, and industrial production is easy to achieve. The formula is defined in the description.
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Paragraph 0029; 0030; 0033; 0034; 0037; 0038
(2017/08/28)
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- N - alkylpiperazine purification of
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PROBLEM TO BE SOLVED: To provide a purification method of N-alkyl piperazines, capable of providing high purity N-alkyl piperazines with low cost and having a high recovery rate.SOLUTION: A mixture of N-alkyl piperazines and a piperazine is distilled in the presence of a polar organic solvent having a higher boiling point than that of the piperazine.
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Paragraph 0054
(2017/02/28)
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- Method for producing N-alkylpiperazine
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PROBLEM TO BE SOLVED: To provide a method for producing N-alkyl piperazines in high yield by selectively alkylating one amino group.SOLUTION: In the method for producing N-alkyl piperazines, piperazines represented by general formula (1) are reacted with a specific alkylating agent in the presence of an acid. In the formula: R-Rare each independently a hydrogen atom, a methyl group, an ethyl group, a 3-8C linear alkyl group or the like, a hydroxyethyl group, a hydroxypropyl group, a dihydroxypropyl group, a methoxy group, an ethoxy group, a phenyl group, a benzyl group, a 2-phenylethyl group, or the like.
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Paragraph 0056; 0062; 0065
(2017/02/09)
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- Method for synthesizing N-hydroxyethylpiperazine and piperazine by means of co-production
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The invention discloses a method for synthesizing N-hydroxyethylpiperazine and piperazine by means of co-production. With diethanolamine and ethanol amine as raw materials, in a solvent and in a fixed bed reactor with a hydrogen service atmosphere, the raw materials are catalyzed to perform cyclization by a catalyst to obtain N-hydroxyethylpiperazine and piperazine. The prepared catalyst has the advantages of good selectivity and long service life. The synthetic method has the advantages of small reaction pressure of the whole process and high safety, can be used for continuous synthesis, and can co-produce piperazine while preparing N-hydroxyethylpiperazine. The prepared products have the quality conforming to the industrial product first-class standards, and the contents of N-hydroxyethylpiperazine and piperazine are not less than 99.5%; the purities of N-hydroxyethylpiperazine and piperazine are 99.0% or more. The method is simple in process and suitable for industrialized continuous production.
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Paragraph 0021; 0024; 0025
(2017/01/12)
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- NMR study of the composition of aqueous 2-aminoethanol solution used for absorption of carbon dioxide from fuel gases
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The compositions of aqueous 2-aminoethanol solutions used in industry for absorption of carbon dioxide resulting from combustion of natural gas have been determined by1H and13C NMR spectroscopy. The absorption process does not involve generally accepted paths of thermal decomposition of the absorbent in the reaction with carbon dioxide, but the main path is non-oxidative decomposition of 2-aminoethanol into ammonia and ethylene oxide. Splitting of the NMR signals of carbamate anion formed by reaction of 2-aminoethanol with carbon dioxide has been rationalized by specific structure of the anion due to intramolecular hydrogen bonding.
- Talzi
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p. 927 - 931
(2016/09/04)
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- Amination process for manufacturing amines using catalyst
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Disclosed is a process for the preparation of an amine (particularly diamines and polyamines) by reacting an alkanolamine or a polyol with ammonia in the presence of a catalyst composed of two active metals from the group of transition metals, namely nickel and chromium supported on a microporous refractory substrate, in a hydrogenated, trickle bed reactor.
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Paragraph 0044-0049
(2014/08/07)
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- Iridium-catalyzed condensation of amines and vicinal diols to substituted piperazines
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A straightforward procedure is described for the synthesis of piperazines from amines and 1,2-diols. The heterocyclization is catalyzed by [Cp*IrCl2]2 and sodium hydrogen carbonate and can be achieved with either toluene or water as solvent. The transformation does not require any stoichiometric additives and only produces water as the byproduct. The reaction can be performed between a 1,2-diamine and a 1,2-diol or by a double condensation between a primary alkylamine and a 1,2-diol. At least one substituent is required on the piperazine ring to achieve the cyclization in good yield. The mechanism is believed to involve dehydrogenation of the 1,2-diol to the α-hydroxy aldehyde, which condenses with the amine to form the α-hydroxy imine. The latter rearranges to the corresponding α-amino carbonyl compound, which then reacts with another amine followed by reduction of the resulting imine. Piperazines are prepared by [Cp*IrCl 2]2-catalyzed heterocyclization of 1,2-diols with either 1,2-diamines or primary alkylamines. The reaction is performed in toluene or water and requires no stoichiometric additive. The key step in the mechanism is believed to be the isomerization of an α-hydroxy imine to the corresponding α-amino carbonyl compound. Copyright
- Lorentz-Petersen, Linda L. R.,Nordstrom, Lars Ulrik,Madsen, Robert
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p. 6752 - 6759
(2013/01/15)
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- SUBSTITUTED PYRIDAZINE CARBOXAMIDE COMPOUNDS
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The new pyridazine derivatives have unexpected drug properties as inhibitors of protein kinases especially against ALK and are useful in treating disorders related to abnormal protein kinase activities such as cancer, neurological and psychiatric diseases
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Page/Page column 41
(2012/04/23)
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- UV-SENSITIVE LITHOGRAPHIC PRINTING PLATE PRECURSOR WITH BENZOXAZOLE DERIVATIVE AND ANALOGUES THEREOF AS SENSITIZER
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Lithographic printing plate precursor comprising (a) a lithographic substrate with a hydrophilic surface and (b) a radiation-sensitive coating on the hydrophilic surface comprising (i) one or more types of monomers and/or oligomers and/or polymers, each comprising at least one ethylenically unsaturated group accessible to a free-radical polymerization, (ii) at least one sensitizer, and (iii) at least one coinitiator capable of forming free radicals together with the sensitizer, said coinitiator being other than metallocenes, characterized in that the at least one sensitizer comprises a compound of formula (I) wherein at least one of the groups R9 to R12 is a bulky group which has a van der Waals volume of at least 55 ?3.
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- METHODS OF MAKING CYCLIC, N-AMINO FUNCTIONAL TRIAMINES
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The present invention provides strategies for making cyclic triamines. Reactant media including certain precursors and/or certain types of catalysts can be converted into cyclic triamines with improved conversion and selectivity. The strategies can be incorporated into reactions that involve transamination schemes and/or reductive amination schemes. In the case of transamination, for instance, using transamination to cause ring closure of higher amines in the presence of a suitable catalyst leads to desired cyclic triamines with notable conversion and yield. In the case of reductive amination, reacting suitable polyfunctional precursors in the presence of a suitable catalyst also yields cyclic triamines via ring closure with notable selectivity and conversion. Both transamination and reductive amination methodologies can be practiced under much milder temperatures than are used when solely acid catalysts are used. Preferred embodiments can produce reaction mixtures that are generally free of salt by-products.
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Page/Page column 30-31
(2010/04/28)
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- Novel antagonists of serotonin-4 receptors: Synthesis and biological evaluation of pyrrolothienopyrazines
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Based on the definition of a 5-HT4 receptor antagonist pharmacophore, a series of pyrrolo[1,2-a]thieno[3,2-e] and pyrrolo[1,2-a]thieno[2,3-e] pyrazine derivatives were designed, prepared, and evaluated to determine the properties necessary for high-affinity binding to 5-HT4 receptors. The compounds were synthesized by substituting the chlorine atom of the pyrazine ring with various N-alkyl-4-piperidinylmethanolates. They were evaluated in binding assays with [3H]GR113808 (1) as the 5-HT4 receptor radioligand. The affinity values (Ki or inhibition percentages) were affected by both the substituent on the aromatic ring and the substituent on the lateral piperidine chain. A methyl group on the tricyclic ring produced a marked increase in affinity while an N-propyl or N-butyl group gave compounds with nanomolar affinities. Among the most potent ligands, 34d was selected for further pharmacological studies and evaluated in vivo. This compound acts as an antagonist/weak partial agonist in COS-7 cells stably expressing the 5-HT4(a) receptor and is of great interest as a peripheral antinociceptive agent.
- Lemaitre, Stephane,Lepailleur, Alban,Bureau, Ronan,Butt-Gueulle, Sabrina,Lelong-Boulouard, Veronique,Duchatelle, Pascal,Boulouard, Michel,Dumuis, Aline,Daveu, Cyril,Lezoualc'h, Frank,Pfeiffer, Bruno,Dauphin, Francois,Rault, Sylvain
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scheme or table
p. 2607 - 2622
(2009/09/06)
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- Sensitizer/Initiator Combination for Negative-Working Thermal-Sensitive Compositions Usable for Lithographic Plates
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The radiation-sensitive composition and the negative working imageable element include a cationic IR absorber with tetraarylborate counteranion and an onium initiator with tetraarylborate counteranion. The use of these components provides high imaging sensitivity, good shelflife and high print run length.
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- Stability studies of some glycolamide ester prodrugs of niflumic acid in aqueous buffers and human plasma by HPLC with UV detection
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Glycolamide esters (compounds 1-17) of 2-(3-trifluoromethyl-phenylamino) nicotinic acid (niflumic acid, CAS 4394-00-7) have been synthesized and evaluated as possible prodrugs. In-vitro hydrolysis studies were conducted at selected pH values (1.2, 3.5, 4.8, 7.4 and 7.8) and in human plasma at 37 ± 0.5 °C using HPLC with UV detection. The aqueous (pH 7.4 and 7.8) and enzymatic rates of hydrolysis were substantially affected by the nature of promoieties in this series. The compounds showed good chemical stability in the buffers of low pH values (1.2, 3.5 and 4.8) and appreciable hydrolysis under alkaline conditions and in human plasma. They exhibited long hydrolytic half-lives of 7-46 h in aqueous buffer solutions (pH 7.4 and 7.8) and 14-21 min in human plasma, respectively. It was observed that N,N-disubstituted and cyclic glycolamide derivatives showed 2 fold more hydrolysis in the alkaline pH than monosubstituted derivatives, whereas the piperidino and thiomorpholino derivatives did not undergo chemical hydrolysis. The compounds contain two possible sites for hydrolysis with an increased hydrolytic susceptibility at the terminal aliphatic carbonyl site in aqueous buffers and human plasma solutions. They were found to be cleaved at two hydrolytic carbonyls, namely the nicotinyl (2-5% in enzymatic hydrolysis) and the aliphatic site (7-55% and 70-85% in buffer and plasma hydrolysis, respectively) as revealed by HPLC analysis. The glycolamide ester prodrugs of niflumic acid underwent chemical and enzymatic hydrolysis to release mainly the metabolite 2- (3-trifluoromethyl-phenylamino) nicotinic acid carboxymethyl ester (III) and not the parent drug 2-(3-trifluoromethyl-phenylamino) nicotinic acid. The structure of the metabolite was confirmed by liquid chromatography-mass spectroscopy (LCMS). ECV · Editio Cantor Verlag.
- Talath, Sirajunisa,Shirote, Pramod J.,Lough, W. John,Gadad, Andanappa K.
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p. 631 - 639
(2008/02/12)
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- METHOD FOR PRODUCING ETHYLENEAMINES
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The invention relates to the production ethyleneamines by reacting monoethanolamine (MEOA) with ammonia in the presence of a catalyst inside a reactor (1) and by separating the resulting reaction discharge. During separation, the ethylenediamine (EDA) obtained is reacted inside a separate reactor (2) in the presence of a catalyst to form diethylenetriamine (DETA), and the resulting reaction discharge is fed to the separation of the reaction discharge resulting from the reactor (1).
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Page/Page column 10; 11
(2008/06/13)
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- Unique spirocyclopiperazinium salt I: Synthesis and structure-activity relationship of spirocyclopiperazinium salts as analgesics
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Based on the structure of compound 3, two series of spirocyclopiperazinium derivatives 7a-n and 10a-h were synthesized and evaluated for their in vivo analgesic and sedative activities. Compounds 7f and 10c were discovered to exhibit excellent analgesic activity. Structure-activity relationships revealed that anion of the quaternary salt affected the analgesic and sedative activity significantly; the allyl group is a most effective group among the compounds 7a-n; the electron-released substitute on the aromatic ring is favorable to increase the analgesic activity.
- Gao, Feng-Li,Wang, Xin,Zhang, Hong-Mei,Cheng, Tie-Ming,Li, Run-Tao
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p. 1535 - 1537
(2007/10/03)
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- SUBSTITUTED QUINAZOLINE DERIVATIVES AND THEIR USE AS INHIBITORS
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The use of a compound of formula (I) 1 or a salt, ester or amide thereof; where X is O, or S, S(O) or S(O)2, or NR6 where R6 is hydrogen or C1-6 alkyl,; R5 is an optionally substituted 5-membered heteroaromatic ring, R1, R2 ,R3, R4 are independently selected from various specified moieties, in the preparation of a medicament for use in the inhibition of aurora 2 kinase. Certain compounds are novel and these, together with pharmaceutical compositions containing them are also described and claimed
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- Method of treating a patient having precancerous lesions with phenyl quinazolinone derivatives
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Derivatives of 2-phenyl quinazolinones are useful for the treatment of patients having precancerous lesions. These compounds are also useful to inhibit growth of neoplastic cells.
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- Pyrazolopyrimidinone cGMP PDE5 inhibitors for the treatment of sexual dysfunction
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Compounds of the formulae (IA) and (IB): wherein R1is C1to C3alkyl optionally substituted with phenyl, Het or a N-linked heterocyclic group selected from piperidinyl and morpholinyl; wherein said phenyl group is optionally substituted by one or more substitutents selected from C1to C4alkoxy; halo; CN; CF3; OCF3or C1to C4alkyl wherein said C1to C4alkyl group is optionally substituted by C1to C4haloalkyl or haloalkoxy either of which is substituted by one or more halo atoms; R2is C1to C6alkyl and R13is OR3or NR5R6, or pharmaceutically or veterinarily acceptable salts thereof, or pharmaceutically or veterinarily acceptable solvates of either entity are potent and selective inhibitors of type 5 cyclic guanosine 3′,5′-monophosphate phosphodiesterase (cGMP PDE5) and have utility in the treatment of, inter alia, male erectile dysfunction (MED) and female sexual dysfunction (FSD).
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- Pyrazolopyrimidinone CGMP PDE5 inhibitors for the treatment of sexual dysfunction
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There is provided compounds of formula IA and of formula IB, wherein R1, R2, R3, R4and A have meanings given in the description, which are useful in the curative and prophylactic treatment of medical conditions for which inhibition of a cyclic guanosine 3′,5′-monophosphate phosphodiesterase (e.g. cGMP PDE5) is desired.
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- Method of treating a patient having precancerous lesions with phenyl cycloamino pyrimidinone derivatives
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Derivatives of Phenyl Cycloamino Pyrimidinone are useful for the treatment of patients having precancerous lesions. These compounds are also useful to inhibit growth of neoplastic cells.
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- Cyclic urea derivatives, pharmaceutical compositions containing these compounds and processes for preparing them
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The invention relates to cyclic urea derivatives of general formula I STR1 wherein Ra, Rb, X and Y are defined as in claim 1, the tautomers, stereoisomers and salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, which have valuable pharmacological properties, preferably aggregation inhibiting effects, and to drugs containing the compounds and processes for preparing them.
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- PYRIDOPYRIMIDINONE ANTIANGINAL AGENTS
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Compounds of the formula and pharmaceutically acceptable salts thereof, wherein R 1 is H, C 1 -C 4 alkyl CN or CONR 4 R 5 ; R 2 is C 2 -C 4 alkyl; R 3 is SO 2 NR 6 R 7, NO 2, NH 2, NHCOR 8 NHSO 2 R 8 or N(SO 2 R 8) 2 ; R 4 and R 5 are each independently selected from H and C 1 -C 4 alkyl; R 6 and R 7 are each independently selected from H and C 1 -C 4 alkyl optionally substituted with CO 2 R 9, OH, pyridyl 5-isoxazolin-3-onyl, morpholino or 1-imidazolidin-2-onyl; or together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino, morpholino, 1-pyrazolyl or 4-(NR 10)-1-piperazinyl group wherein any of said groups may optionally be substituted with one or two substituents selected from C 1 -C 4 alkyl, CO 2 R 9, NH 2 and OH; R 8 is C 1 -C 4 alkyl or pyridyl; R 9 is H or C 1 -C 4 alkyl; and R 10 is H, C 1 -C 4 alkyl or (hydroxy) C 2 -C 3 alkyl; are selected cGMP PDE inhibitors useful in the treatment of, inter alia, cardiovascular disorders such as angina, hypertension, heart failure and atherosclerosis
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- QUINAZOLINONE ANTIANGINAL AGENTS
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Compounds of formula: and pharmaceutically acceptable salts thereofwhereinR1 is H, Q - Q alkyl, C j -Q alkoxy or CONRsRs;R2 is H or- CJ-C4 alkyl;R3 is C2-C4 alkyl;R4 is H, C2-C4 alkanoyl optionally substituted withNR7R8, (hydroxy)C2-C4 alkyl optionally substitutedwith NR7R8, CH=CHC02R9, CH=CHCONR7R8,CH2CH2C02R9, CH2CH2CONR7R8, S02NR7R8,S02NH(CH2)nNR7R8 or imidazolyl;R5 and Rs are each independently H or C1-C4 alkyl;R7 and R8 are each independently H or C1-C4 alkyl, ortogether with the nitrogen atom to which they areattached form a pyrrolidino, piperidino, morpholino or4-(NR10)-l-piperazinyl group wherein any of saidgroups is optionally substituted with CONR5R6;R9 is H or C1-C4 alkyl;R10 is H, C1-C3 alkyl or (hydroxy)C2-C3 alkyl; andn is 2, 3 or 4;with the proviso that R4 is not H when R1 is H, C1-C4 alkylor C1-C4 alkoxy; are selective cGMP PDE inhibitors usefiilin the treatment of cardiovascular disorders such as angina, hypertension, heart failure and atherosclerosis.
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- Kinetics and mechanism of the aminolysis of phenyl and 4-nitrophenyl ethyl thionocarbonates
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The reactions of the title substrates (PTOC and NPTOC, respectively) with secondary alicyclic amines are subjected to a kinetic study in aqueous solution at 25.0°C, ionic strength 0.2 M (KCl). Under amine excess, pseudo-first-order rate coefficients (kobsd) are found throughout. The order in amine is one for the reactions of piperidine but is of intermediate order between 1 and 2 for the reactions of the other amines. The kinetic results can be accommodated by a reaction scheme with two hypothetical tetrahedral intermediates: a zwitterionic (T±) and an anionic (T-) one, whereby amine catalysis (deprotonation of T± to give T-) is kinetically important. Both the pKa of T± and the rate coefficient for proton transfer (k3 ca. 1010 s-1 M-1) are estimated. The values of the other rate microcoefficients of the scheme are found by a nonlinear least-squares fitting, and these values are compared with those exhibited in the aminolysis of phenyl thionoacetate (PTOA), and S-phenyl and S-(4-nitrophenyl) O-ethyl dithiocarbonates (PDTC and NPDTC, respectively). The Broensted type plots for amine basicity have slopes βN ca. 0.2 for rate-determining amine attack (k1) and βN ca. 0.8 for amine expulsion from T± (k-1), in accord with the βN values found in similar aminolyses. The general base catalysis by amine found in the aminolysis of NPTOC, in contrast with the lack of such catalysis in the aminolysis of 4-nitrophenyl methyl carbonate, is explained by a smaller rate coefficient for expulsion of 4-nitrophenoxide (k2) from T±(which competes with amine deprotonation of T±) relative to the same expulsion from the analogous oxy intermediate.
- Castro, Enrique A.,Cubillos, Maria,Santos, Jose G.
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p. 3501 - 3505
(2007/10/03)
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- Selective deprotection of allyl amines using palladium
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Mono and diallylamines can be cleaved using Pdf(0) catalyst and 2-mercaptobenzoic acid as nucleophile. This methodology has been successfully used for the sequential deprotection of diallylamines. The yields of desallylation are good to quantitative.
- Lemaire-Audoire,Lemaire-Audoire, Sandrine,Savignac,Savignac, Monique,Genet,Genet, Jean Pierre,Bernard,Bernard, Jean-Marie
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p. 1267 - 1270
(2007/10/02)
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- Process for converting heat stable amine salts to heat regenerable amine salts
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Processes are disclosed for converting heat stable amine salts to heat regenerable amine salts using a modified electrodialysis zone (140). The processes of the present invention can be used to reduce the level of heat stable salts in a lean solvent stream in an acid gas removal process and can be integrated with the acid gas removal process to utilize process streams as a source of ions.
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- Pharmaceutical compositions of N-heterocyclic benzenesulfonamides and their use
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The invention relates to new N-cyclic benzenesulfonamides, their process of preparation and their use as active substance of pharmaceutical compositions. The new benzenesulfonamides according to the invention correspond to the following general formula (I): STR1 in which: V represents, for example, hydrogen, W represents, for example CF3, X represents, for example, hydrogen, Y represents, for example, hydrogen, n is 2 or 3, Z represents, for example, the group NR4, in which R4 represents, for example, hydrogen. These compounds are useful in pharmaceutical compositions for the treatment of nervous disorders with anxiety.
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- Use of cyclic thiazines as microbiocides
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Cyclic thiazines of the formula STR1 where the R's are hydrogen or a substituted group such as a hydrocarbon group, i.e., alkyl, etc. and N is a cyclic moiety, Z is S, STR2 and X is an anion, are prepared by reacting a cyclic secondary amine salt with a divinyl sulfur compound. These are illustrated by the reaction of piperidine hydrochloride with divinyl sulfone to yield STR3 These products have a wide variety of uses including their use as microbiocides, etc.
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