- Synthesis method of dapoxetine
-
The present invention provides a synthesis method of dapoxetine, comprising the following steps: S1, the (s)-3-amino-3-phenylpropionic acid or ester compounds dispersed in a solvent, reflux reaction under the action of a reducing agent, to give (s) - amino-3-phenylpropanol; S2, the (s) - amino-3-phenylpropanol dissolved in aqueous solution of carboxylic acid, added paraformaldehyde to warm up the reaction, to give (s) -3-dimethylamino-3-phenylpropanol; S3, (s)-3-Dimethylamino-3-phenylpropanol was dissolved in a solvent, protected by nitrogen, and reacted in a solution of alkali added dropwise at a higher temperature, and then 1-fluoronaphthalene was added to produce Williamson etherization reaction, to give (s)-N, N-dimethyl-3-(1-naphthooxy) amphetamine, i.e., dapoxetine. The synthesis method of dapoxetine of the present invention is inexpensive and easy to obtain raw materials, does not use toxic and dangerous reagents, will not react to the phenomenon of aggregation spray, the process is simple, suitable for industrial production.
- -
-
Paragraph 0040-0042; 0051-0052; 0061
(2022/01/12)
-
- Base-induced Sommelet–Hauser rearrangement of N-(α-(2-oxyethyl)branched)benzylic glycine ester-derived ammonium salts via a chelated intermediate
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The base-induced Sommelet–Hauser (S–H) rearrangement of N-(α-branched)benzylic glycine ester-derived ammonium salts 1 was investigated. When the α-branched substituent was a simple alkyl, such as a methyl or butyl, desired S–H rearrangement product 2 was obtained in low yield with formation of the [1,2] Stevens rearranged 4 and Hofmann eliminated products 5 and 6. However, when the α-branched substituent had a 2-oxy moiety, such as 2-acetoxyethyl or 2-benzoyloxyethyl, the yields of 2 were improved. These results could be explained by formation of chelated intermediate C that stabilizes the carbanionic ylide, and the subsequent initial dearomative [2,3] sigmatropic rearrangement would be accelerated. The existence of C was supported by mechanistic experiments. This enhancement effect is not very strong or effective; however, it will expand the synthetic usefulness of ammonium ylide rearrangements.
- Baba, Souya,Hirano, Kazuki,Tayama, Eiji
-
supporting information
(2020/03/13)
-
- Synthetic method of dapoxetine and intermediate thereof
-
The invention discloses a synthetic method of dapoxetine and its intermediate, i.e., (S)-3-(tert-butyloxycarbonyl)amino-3-phenylpropanol as shown in a formula 5 which is described in the specification. The synthetic method of (S)-3-(tert-butyloxycarbonyl)amino-3-phenylpropanol is as shown in a synthesis route which is described in the specification, wherein a compound 3 and acetaldehyde are subjected to a Mannich reaction in an organic solvent under the action of a supramolecular catalyst constructed by a chiral catalyst and a polymer so as to obtain a compound 4, and the polymer is at least one selected from of the group consisting of PEG 200, PEG 400, PEG 600, MeOPEG 750, PEG 800, PEG 1000, PPG 800 and PPG 1000. The dapoxetine is synthesized from the (S)-3-(tert-butyloxycarbonyl)amino-3-phenylpropanol prepared by using the above method according to steps as shown in the synthesis route. The synthetic method of dapoxetine and the intermediate thereof has the characteristics of usage of cheap and easily available raw materials, high yield and low cost, and is more beneficial to industrial production.
- -
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-
- Site-Specific C(sp3)–H Aminations of Imidates and Amidines Enabled by Covalently Tethered Distonic Radical Anions
-
The utilization of N-centered radicals to synthesize nitrogen-containing compounds has attracted considerable attention recently, due to their powerful reactivities and the concomitant construction of C?N bonds. However, the generation and control of N-centered radicals remain particularly challenging. We report a tethering strategy using SOMO-HOMO-converted distonic radical anions for the site-specific aminations of imidates and amidines with aid of the non-covalent interaction. This reaction features a remarkably broad substrate scope and also enables the late-stage functionalization of bioactive molecules. Furthermore, the reaction mechanism is thoroughly investigated through kinetic studies, Raman spectroscopy, electron paramagnetic resonance spectroscopy, and density functional theory calculations, revealing that the aminations likely involve direct homolytic cleavage of N?H bonds and subsequently controllable 1,5 or 1,6 hydrogen atom transfer.
- Fang, Yuanding,Fu, Kang,Shi, Lei,Zhao, Rong,Zhou, Jia
-
p. 20682 - 20690
(2020/09/07)
-
- Method for preparing amino alcohol compound by using halogenated intermediate
-
The invention discloses a method for preparing an amino alcohol compound by utilizing a halogenated intermediate. According to the method, an oxygen-halogen bond can be prepared by utilizing cyclic diacyl peroxide and halogenated salt under an illumination condition, and the oxygen-halogen bond is prone to homolysis under an illumination condition to form an active free radical, so the amino alcohol is finally prepared. The novel method for synthesizing the amino alcohol is high in atom utilization rate, simple in synthesis method and high in yield, so the consumption of halide for reactions with synthesis values is reduced, and the purposes of environmental protection and green chemistry are better achieved.
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- Lipophilic NHC assisted one-pot synthesis of syncarpamide analogues in aqueous medium
-
Lipophilic NHC catalysis in aqueous medium was reported for the synthesis of biologically relevant (a)symmetrically substituted and unsymmetrically substituted syncarpamide analogues. All the reported reactions were performed in the absence of any expensive metal salts or additives. A diverse array of syncarpamide analogues was obtained in good yields. Lipophilic NHC catalysis was also extended to chemoselective transesterification reactions.
- Suresh, Pavithira,Selva Ganesan, Subramaniapillai
-
supporting information
p. 6257 - 6261
(2019/04/25)
-
- COMPOUNDS AND USES THEREOF
-
The present invention features compounds useful in the treatment of neurological disorders. The compounds of the invention, alone or in combination with other pharmaceutically active agents, can be used for treating or preventing neurological disorders.
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-
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- 5-hydroxytryptamine re-absorption inhibitor crystal form and preparation method thereof
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The invention relates to a dapoxetine hydrochloride crystal form and a preparation method thereof, and belongs to the technical field of drug synthesis. The preparation method comprises: dissolving (S)-3-amino-3-phenylpropionic acid in an appropriate solvent, adding a reducing agent and a Lewis acid, and reducing to obtain (S)-3-amino-3-phenylpropanol; dissolving the (S)-3-amino-3-phenylpropanolin formic acid, and adding formaldehyde to produce (S)-3-dimethylamino-3-phenylpropanol; dissolving the (S)-3-dimethylamino-3-phenylpropanol in an organic solvent, adding an alkali and 1-fluoronaphthalene, carrying out heating stirring for 5-10 h, adding water and an organic solvent, extracting, carrying out spin drying on the organic phase, dissolving with a solvent, adding concentrated hydrochloric acid in a dropwise manner, and carrying out pressure reducing distillation to remove the solvent and the water; and re-crystallizing with a suitable solvent to obtain the dapoxetine hydrochloride.According to the present invention, the Cu-Ka radiation results of the obtained dapoxetine hydrochloride crystal form show that the characteristic peaks represented by 2[theta] angle are positioned at 6.24+/-0.2, 15.03+/-0.2, 18.87+/-0.2, 20.63+/-0.2 and 25.28+/-0.2 in the X-ray powder diffraction pattern.
- -
-
Paragraph 0045-0054
(2019/08/30)
-
- Preparation method of 3-aminopropanol or 3-aminopropionic acid derivative
-
The invention provides a preparation method of an optically active 3-aminopropanol or 3-aminopropionic acid derivative, and belongs to the technical field of organic synthesis. A compound having a structure as shown in a formula II and a formula III is used as a raw material, and the optically active 3-aminopropanol or 3-aminopropionic acid derivative is obtained through four basic steps, namely dehydration condensation, hydrogenation reduction, reduction and hydrolysis. The raw materials adopted in the preparation method are easy to obtain and low in cost; as a chiral phosphine-transitional metal catalyst is used in the hydrogenation reduction reaction, the optically active 3-aminopropanol or 3-aminopropionic acid derivative is efficient, high in selectivity, low in cost and suitable forlarge-scale production. Compared with existing chemical resolution and chiral introduction, the asymmetric hydrogenation synthesis method provided by the invention only produces one chiral product, ishigh in yield, and has relatively high advantages in economy and raw material utilization rate.
- -
-
-
- Method for preparing dapoxetine hydrochloride
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The invention discloses a method for preparing dapoxetine hydrochloride. The method comprises the following steps: subjecting (s)-3-amino-3-phenylpropionic acid or an ester thereof to a reduction reaction in a reduction system prepared from a hydroborate and a boron trifluoride complex, so as to obtain an intermediate 1, i.e. (s)-3-amino-3-phenylpropanol; subjecting the (s) intermediate 1 to an Eschweiler-Clark reaction with formic acid and formaldehyde, so as to obtain an intermediate 2; subjecting the intermediate 2 to a Williamson ether forming reaction with 1-fluoronaphthalene, so as to obtain a free alkali, i.e. (s)-N,N-dimethyl-3-(1-naphthyloxy)phenyl propyl amine; subjecting the free alkali to a salt forming reaction with alcohol-acyl chloride or a chloride thereof, a hydrochloric acid organic solution or hydrochloric acid gas, thereby obtaining dapoxetine hydrochloride. According to the method, the synthesis route is low in production cost, the reaction conditions are mild, all the materials are readily available, the raw materials are low in toxicity, the reaction is simple in operation and high in safety, and the product is high in purity and yield and is environmentally friendly, so that the method is applicable to industrial large-scale production.
- -
-
Paragraph 0048-0049; 0095-0096
(2017/07/22)
-
- Synthesis, separation-purification, and salt forming method of dapoxetine
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The invention provides a novel synthesis, gradient separation-purification, and salt forming method of dapoxetine. Easily available and cheap benzaldehyde is taken as the primary raw material of the synthesis route. The whole reaction conditions are mild. The synthesis route is short. No highly toxic or explosive raw material is used. The problem of chiral separation is well solved in the route. During the separation process, the product is purified. Finally, chlorinated hydromethyl tert-butyl ether which does not have any side or toxic effect is used to carry out salt forming. A large amount of labor, material, and time is saved. The production cost is reduced. The synthesis does not need any special equipment. The operation is simple and convenient. The method has a good industrial application prospect.
- -
-
Paragraph 0034; 0041
(2017/07/20)
-
- A chiral analog of the bicyclic guanidine TBD: Synthesis, structure and Br?nsted base catalysis
-
Starting from (S)-β-phenylalanine, easily accessible by lipase-catalyzed kinetic resolution, a chiral triamine was assembled by a reductive amination and finally cyclized to form the title compound 10. In the crystals of the guanidinium benzoate salt the six membered rings of 10 adopt conformations close to an envelope with the phenyl substituents in pseudo-axial positions. The unprotonated guanidine 10 catalyzes Diels-Alder reactions of anthrones and maleimides (25-30% ee). It also promotes as a strong Br?nsted base the retro-aldol reaction of some cycloadducts with kinetic resolution of the enantiomers. In three cases, the retroaldol products (48-83% ee) could be recrystallized to high enantiopurity (≥95% ee). The absolute configuration of several compounds is supported by anomalous X-ray diffraction and by chemical correlation.
- Goldberg, Mariano,Sartakov, Denis,Bats, Jan W.,Bolte, Michael,G?bel, Michael W.
-
supporting information
p. 1870 - 1876
(2016/10/05)
-
- A S - west reaches anchors the sandbank and its salt synthesis method
-
The invention discloses a synthetic method for S-dapoxetine. The synthetic method comprises the following steps: (1) resolving 1-phenyl-3-(naphthyl-1-oxy)propylamine for at least once with a resolving agent to obtain a resolved mixed system; (2) separating the resolved mixed system to obtain S-1-phenyl-3-(naphthyl-1-oxy)propylamine, and recycling mother liquor; (3) performing methylation on the S-1-phenyl-3-(naphthyl-1-oxy)propylamine to obtain S-dapoxetine. Compared with the conventional industrial production method, residual intermediate (R)-phenyl-3-(naphthyl-1-oxy)propylamine in the resolved mother liquor is firstly recycled on the basis of the prior art, then resolved again through D-(-) tartaric acid after racemization, and recycled, so that the yield is increased, the product waste is avoided, and the economic benefits are improved.
- -
-
Paragraph 0061-0062
(2017/04/03)
-
- Process for preparation of enantiomerically pure S-(+)-N, N-dimethyl-a-[2-(naphthalenyloxy)ethyl] benzenemethanamine
-
The present invention relates to improved, efficient process for the preparation of enantiomerically pure S-(+)-N,N-dimethyl-a-[2-(naphthalenyloxy)ethyl] benzenemethanamine and pharmaceutically acid addition salts thereof. The present invention particularly provides a process for preparation of (3S, 4R)-3-hydroxy-1-(4-methoxyphenyl)-4-phenylazetidin-2-one useful as a key intermediate for preparation of (s)-dapoxetine.
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-
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- Iodine mediated deprotection of N-tert-butanesulfinyl amines: A functional group compatible method
-
In the presence of iodine, a functional group compatible method for the deprotection of tert-butanesulfinyl and p-toluenesulfinyl units was developed. This journal is the Partner Organisations 2014.
- Chen, Wen,Ren, Jian,Wang, Minshou,Dang, Lingjing,Shen, Xianfu,Yang, Xiaodong,Zhang, Hongbin
-
supporting information
p. 6259 - 6262
(2014/06/09)
-
- Syntheses of a flobufen metabolite and dapoxetine based on enantioselective allylation of aromatic aldehydes
-
The enantioselective allylation of an aromatic aldehyde to give a chiral homoallylic alcohol was employed as the key step in the syntheses of a flobufen metabolite and dapoxetine. In the former case, the homoallylic alcohol moiety (99 % ee) was converted into a five-membered lactone ring with good preservation of the optical purity, and the target compound, a flobufen metabolite, was obtained in 95 % ee. In the latter case, the homoallylic alcohol moiety (97 % ee) was transformed over several steps into a 3-aminopropanol moiety. During the course of the synthesis, the gradual loss of optical purity was observed, and the target compound, dapoxetine, was obtained in 85 % ee. The enantioselective allylation of an aromatic aldehyde to give the corresponding homoallylic alcohol was the key step in the syntheses of a flobufen metabolite and dapoxetine. In the first case, the homoallylic moiety was converted into a chiral five-membered lactone ring. In the second case, it was transformed into a chiral 1,3-amino alcohol moiety. Copyright
- Hessler, Filip,Korotvicka, Ales,Necas, David,Valterova, Irena,Kotora, Martin
-
p. 2543 - 2548
(2014/05/06)
-
- Synthesis and biological evaluation of novel piperidin-4-ol derivatives
-
A series of novel piperidin-4-ol derivatives were designed, synthesized, and evaluated for potential treatment of HIV. The compounds were obtained via an efficient synthetic route in excellent yields and have been characterized by 1H NMR, 13C NMR, MS, and elemental analysis. The CCR5 antagonistic activities of the compounds have also been evaluated.
- Weng, Zhiyong,Wei, Wei,Dong, Xiaowu,Hu, Yongzhou,Huang, Shufang,Liu, Tao,Xie, Xin
-
scheme or table
p. 303 - 308
(2012/07/03)
-
- PROCESSES FOR THE PREPARATION OF (+)-N,N-DIMETHYL-2-[1-(NAPHTHALENYLOXY) ETHYL] BENZENE METHANAMINE AND INTERMEDIATES THEREOF
-
The present invention relates to processes for the preparation of S(+)-N,N-dimethyl-2-[1-(naphthalenyloxy)ethyl]benzene methanamine and intermediates thereof. More particularly the present invention relates to preparation of the compound 3(S)-(+)-N,N-dimethylamino-3-phenyl propanol useful as intermediate in the synthesis of pharmaceutically active compounds.
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Page/Page column 22
(2012/01/13)
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- Synthesis of heterocycles through a ruthenium-catalyzed tandem ring-closing metathesis/isomerization/N-acyliminium cyclization sequence
-
Tandem bicycle: In the title reaction double bonds created during ring-closing metathesis isomerize to generate reactive iminium intermediates that undergo intramolecular cyclization reactions with tethered heteroatom and carbon nucleophiles. In this way, a series of biologically interesting heterocyclic compounds can be made, including a known precursor for the total synthesis of the antiparasitic natural product harmicine. Copyright
- Ascic, Erhad,Jensen, Jakob F.,Nielsen, Thomas E.
-
supporting information; experimental part
p. 5188 - 5191
(2011/06/26)
-
- Stereoselective chemoenzymatic preparation of β-amino esters: Molecular modelling considerations in lipase-mediated processes and application to the synthesis of (S)-dapoxetine
-
A wide range of optically active 3-amino-3-arylpropanoic acid derivatives have been prepared by means of a stereoselective chemoenzymatic route. The key step is the kinetic resolution of the corresponding β-amino esters. Although the enzymatic acylations of the amino group with ethyl methoxyacetate showed synthetically useful enantioselectivities, the hydrolyses of the ester group catalyzed by lipase from Pseudomonas cepacia have been identified as the optimal processes concerning both activity and enantioselectivity. The enantiopreference of this lipase in these reactions has been explained, at the molecular level, by using a fragment-based approach in which the most favoured binding site for a phenyl ring and the most stable conformation of the 3-aminopropanoate core nicely match the (S)-configuration of the major products. The conversion and enantioselectivity values of the enzymatic reactions have been compared in order to understand the influence of the different substitution patterns present in the phenyl ring. This chemoenzymatic route has been successfully applied to the preparation of a valuable intermediate in the synthesis of (S)-dapoxetine, which has been chemically synthesised in excellent optical purity.
- Rodriguez-Mata, Maria,Garcia-Urdiales, Eduardo,Gotor-Fernandez, Vicente,Gotor, Vicente
-
scheme or table
p. 395 - 406
(2010/06/15)
-
- Efficient and regioselective synthesis of 5-hydroxy-2-isoxazolines: Versatile synthons for isoxazoles, β-lactams, and γ-amino alcohols
-
"Chemical Equation Presented" An efficient and highly regioselective protocol was developed for the preparation of 5-hydroxy2-isoxazolines, which have been proved to be versatile synthons for isoxazles, β-hydroxy oximes, and γ-amino alcohols. β-Lactams, commonly embedded in the skeletons of bioactive natural products, were also synthesized in two steps from β-hydroxy oximes, providing a new strategy for the synthesis of this kind of compounds.
- Tang, Shibing,He, Jinmei,Sun, Yongquan,He, Liuer,She, Xuegong
-
supporting information; experimental part
p. 1961 - 1966
(2010/06/20)
-
- Highly efficient, enantioselective syntheses of (S)-(+)- and (R)-(-)-dapoxetine starting with 3-phenyl-1-propanol
-
(Chemical Equation Presented) A highly efficient, enantioselective sequence has been developed for the synthesis of (S)- and (R)-dapoxetine. The pathways involve the intermediacy of the 6-membered-ring sulfamate esters 4, which were generated by Du Bois asymmetric C-Hamination reactions of the prochiral sulfamate 3, catalyzed by the chiral dirhodium(II) complexes. During the course of our research, the absolute configuration of the enantiomer of 4-pheny[1,2,3]oxathiazinane 2,2-dioxide (4r), prepared by the Du Bois asymmetric C-H amination reaction of 3 and the Rh2(S-nap)4 catalyst, is determined to be R and not S as was originally reported.
- Kang, Soyeong,Lee, Hyeon-Kyu
-
supporting information; experimental part
p. 237 - 240
(2010/04/06)
-
- An efficient formal synthesis of (S)-dapoxetine from enantiopure 3-hydroxy azetidin-2-one
-
An efficient formal synthesis of S-(+) dapoxetine starting from 3-hydroxy azetidin-2-one is described. The intermediate (S)-3-(dimethyl amino)-3-phenylpropan-1-ol was synthesized in enantiopure form starting with 3-hydroxy azetidin-2-one in seven steps.
- Chincholkar, Pinak M.,Kale, Ajaykumar S.,Gumaste, Vikas K.,Deshmukh, Abdul Rakeeb A.S.
-
experimental part
p. 2605 - 2609
(2009/08/08)
-
- Enantioselective synthesis of (S)-dapoxetine
-
An efficient enantioselective synthesis leading directly to (+)-(S)-dapoxetine has been described for the first time using a Sharpless asymmetric dihydroxylation, Barton-McCombie deoxygention, and Mitsunobu reaction as the key steps.
- Siddiqui, Shafi A.,Srinivasan, Kumar V.
-
p. 2099 - 2103
(2008/02/11)
-
- Preparation of enantiomerically pure (R)- and (S)-3-amino-3-phenyl-1- propanol via resolution with immobilized penicillin G acylase
-
Ethyl 2,4-dioxo-4-phenylbutyrate, obtained by condensation of acetophenone with diethyl oxalate, was converted to 3-oxo-3-phenyl-1-propanol in 90% yield by reaction with baker's yeast. Reductive amination with sodium cyanoborohydride in the presence of ammonium acetate gave the racemic 3-amino-3-phenyl-1-propanol in 65% yield. Enzymatic resolution of the corresponding N-phenylacetyl derivative with penicillin G acylase, immobilized on an epoxy resin gave (S)-amide and (R)-amino alcohol in high enantiomeric purity (ee >99%) and >45% yields for each enantiomer.
- Fadnavis, Nitin W.,Radhika, Kasiraman R.,Vedamayee Devi
-
p. 240 - 244
(2007/10/03)
-
- Lipase-catalyzed resolution of chiral 1,3-amino alcohols: application in the asymmetric synthesis of (S)-dapoxetine
-
The enzymatic resolution of 3-amino-3-phenylpropan-1-ol derivatives has been studied through acylation processes. Candida antarctica lipase A (CAL-A) has been identified as the best biocatalyst for the transesterification reaction of 3-amino-3-phenyl-1-tert-butyldimethylsilyloxy-propan-1-ol using ethyl methoxyacetate as acylating agent and tert-butyl methyl ether as solvent. This enzymatic study has allowed us to obtain a valuable intermediate for the production of (S)-dapoxetine, which has been synthesized in good overall yield and high enantiomeric excess.
- Torre, Oliver,Gotor-Fernandez, Vicente,Gotor, Vicente
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p. 860 - 866
(2007/10/03)
-
- Ruthenium-catalyzed asymmetric epoxidation of olefins using H 2O2, part I: Synthesis of new chiral N,N,N,-tridentate pybox and pyboxazine ligands and their ruthenium complexes
-
The synthesis of chiral tridentate N,N,N-pyridine-2.6-bisoxazolines 3 (pyhox ligands) and N,N,N-pyridine-2.6-bisoxazines 4 (pyboxazine ligands) is described in detail. These novel ligands constitute a useful tool-box for the application in asymmetric catalysis. Compounds 3 and 4 are conveniently prepared by cyclization of enantiomerically pure α- or β-amino al cohols with dimethyl pyridine-2,6-dicarboximidate. The corresponding ruthenium complexes are efficient asymmetric epoxidation catalysts and have been prepared in good yield and fully char acterized by spectroscopic means. Four of these ruthenium complexes have been characterized by X-ray crystallography. For the first time the molecular structure of a pyboxazine complex (2,6-bis-[(4S)-4-phenyl-5,6- dihydro-4H-[1,3]oxazinyl]pyridine)(pyridine-2,6-dicarboxylate)ruthenium (S)-2aa, is presented.
- Tse, Man Kin,Bhor, Santosh,Klawonn, Markus,Anilkumar, Gopinathan,Jiao, Haijun,Doebler, Christian,Spannenberg, Anke,Magerlein, Wolfgang,Hugl, Herbert,Beller, Matthias
-
p. 1855 - 1874
(2008/02/02)
-
- Novel phosphorus-containing prodrug
-
Novel cyclic phosphoramidate prodrugs of parent drugs MH of formula I their use in delivery of drugs to the liver, their use in enhancing oral bioavailability, and their method of preparation are described.
- -
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Page/Page column 66
(2010/11/08)
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- TUBULIN INHIBITORS
-
Compounds of general formula (I), (II) (III) and (V) are described for use in modulating microtubule polymerisation and in the treatment of associated disease states. Use of compounds (I), (III) and (V) in the treatment of kinase-associated disease states is also described. Further described are novel compounds of formula (II), (III) and (V).
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Page/Page column 42
(2008/06/13)
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- Structure-activity relationships of 1,3,5-triazine-2,4,6-triones as human gonadotropin-releasing hormone receptor antagonists
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SAR studies of 1,3,5-triazine-2,4,6-triones as human gonadotropin-releasing hormone receptor antagonists resulted in potent compounds. The best compound from the series had a binding affinity of 2 nM.
- Guo, Zhiqiang,Wu, Dongpei,Zhu, Yun-Fei,Tucci, Fabio C.,Regan, Collin F.,Rowbottom, Martin W.,Struthers, R. Scott,Xie, Qiu,Reijmers, Shelby,Sullivan, Susan K.,Sai, Yang,Chen, Chen
-
p. 3685 - 3690
(2007/10/03)
-
- Kinetic and NMR spectroscopic studies of chiral mixed sodium/lithium amides used for the deprotonation of cyclohexene oxide
-
The mixed-metal complex formed from n-butylsodium, n-butyllithium, and a chiral amino ether has been studied by NMR spectroscopy. Three different mixed-metal amides were used as chiral bases for the deprotonation of cyclohexene oxide. The selectivity and initial rate of reaction were compared for sodium-amido ethers, lithium-amido ethers, and mixtures of sodium and lithiumamido ethers in diethyl ether and tetrahydrofuran, respectively. The mixed sodium/lithium amides are more reactive than the single sodium and lithium amides, whereas the stereoselectivities are higher when lithium amides are used. The alkali-metal/γ-amido ethers exhibit both higher initial reaction rates and stereoselectivities than their β-amido ether analogues. NMR spectroscopic studies of mixtures of n-butylsodium (nBuNa), n-butyllithium (nBuLi), and the γ-amino ethers in diethyl ether show the exclusive formation of dimeric mixed-metal amides. In diethyl ether, the lithium atom of the mixed-metal amide is internally coordinated and the sodium atom is exposed to solvent; however, in tetrahydrofuran, both metals are internally coordinated.
- Sott, Richard,Granander, Johan,Williamson, Carl,Hilmersson, Goeran
-
p. 4785 - 4792
(2007/10/03)
-
- PYRAZINE-BASED TUBULIN INHIBITORS
-
A compound of general formula (I) or pharmaceutically acceptable prodrugs, salts, hydrates, solvates, crystal forms or diastereomers thereof is described. A method of treating a hyperproliferation-related disease state or disorder in a subject using a compound of formula (I) is also described
- -
-
-
- A convenient synthesis of dihydro- and tetrahydro-1,3-thiazine derivatives from β-aryl-β-amino acids
-
A facile synthesis of 2-alkyl-4-aryl-5,6-dihydro-4H-1,3-thiazines and cis-2-alkyl-4-aryl-3,4,5,6-tetrahydro-2H-1,3-thiazines with potential therapeutic interest was achieved starting from readily accessible β-aryl-β-amino acids.
- Leflemme, Nicolas,Dallemagne, Patrick,Rault, Sylvain
-
p. 1503 - 1505
(2007/10/03)
-
- Dutch Resolution: Separation of enantiomers with families of resolving agents. A status report
-
Dutch Resolution is the term given to the use of mixtures (families) of resolving agents in classical resolutions. In this status report an overview is given of the latest results and new (possible) families of resolving agents are introduced. The concept of families is discussed as well as the factors that come into play on use of families. Practical aspects of Dutch Resolution in particular and resolutions in general are discussed.
- Kellogg, Richard M.,Nieuwenhuijzen, Jose W.,Pouwer,Vries, Ton R.,Broxterman, Quirinus B.,Grimbergen, Reinier F.P.,Kaptein, Bernard,La Crois, Rene M.,De Wever, Ellen,Zwaagstra, Karen,Van Der Laan, Alexander C.
-
p. 1626 - 1638
(2007/10/03)
-
- Synthesis of enantiomerically pure amino-substituted fused bicyclic rings
-
This invention describes various processes for synthesis and resolution of racemic amino-substituted fused bicyclic ring systems. One process utilizes selective hydrogenation of an amino-substituted fused bicyclic aromatic ring system. An alternative process prepares the racemic amino-substituted fused bicyclic ring system via nitrosation. In addition, the present invention describes the enzymatic resolution of a racemic mixture to produce the (R)- and (S)-forms of amino-substituted fused bicyclic rings as well as a racemization process to recycle the unpreferred enantioner. Further provided by this invention is an asymmetric synthesis of the (R)- or (S)-enantiomer of primary amino-substituted fused bicyclic ring systems.
- -
-
-
- Reaction of 1,3-dioxanes with acetone cyanohydrin
-
The reaction of 4-phenyl- and 4,4-dimethyl-1,3-dioxanes with acetone cyanohydrin leads to hydrolytically unstable 2-(1-hydroxy-1-methylethyl)-5,6-dihydro-1,3-oxazines, which are readily saponified in alkaline medium to the corresponding 1,3-amino alcohols
- Kuznetsov,Brusilovskii
-
p. 574 - 575
(2007/10/03)
-
- Substituted imidazolidine derivatives, their preparation, their use and pharmaceutical preparations including them
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Substituted imidazolidine derivatives of the formula I, in which B, E, W, Y, R, R2, R3, R30, e and h have the meanings indicated in the claims. The compounds of the formula I are valuable pharmaceutical active compounds, which are suitable, for example, for the therapy of inflammatory disorders, for example of rheumatoid arthritis, or of allergic disorders. The compounds of the formula I are inhibitors of the adhesion and migration of leucocytes and/or antagonists of the adhesion receptor VLA-4 belonging to the integrins group. They are generally suitable for the therapy or prophylaxis of illnesses which are caused by an undesired extent of leucocyte adhesion and/or leucocyte migration or are associated therewith, or in which cell-cell or cell-matrix interactions which are based on interactions of VLA-4 receptors with their ligands play a part. The invention furthermore relates to processes for the preparation of the compounds of the formula I, their use, in particular as pharmaceutical active compounds, and pharmaceutical preparations which contain compounds of the formula I.
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- Precursors for the production of chiral 1,3-aminoalcohols
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The disclosure describes novel precursors for the preparation of chiral 1,3-aminoalcohols. The precursors are chiral 4-hydroxycarboxamides, 4-hydroxyhydroxamic acids, or 4-hydroxyhydrazides produced from chiral gamma-lactones, which in turn are derived from 1,4-diols by stereoselective oxidation. The chiral 4-hydroxycarboxamides, 4-hydroxyhydroxamic acids, or 4-hydroxyhydrazides are converted into chiral 1,3-aminoalcohols by stereospecific rearrangement.
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- Studies on the asymmetric reduction of β-oximino methyl ether boronates: Reagent control, double diastereocontrol and transmitted remote asymmetric induction
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High asymmetric induction (94% ee) could be obtained in the reduction of the achiral E-oxime ether boronate 5 with a homochiral oxazaborolidine 13-BH3-THF complex. Application of this homochiral reducing agent system to non-aromatic oxime ethers 21 produced low to moderate asymmetric induction. Application of the same homochiral reducing agent system to reduction of homochiral boronate E-oximes 3 and 4 produced extreme double diastereo-selection effects, i.e. 8 and 95% ee respectively, which demonstrated that remote asymmetry was being 'transmitted' by a suitable choice of a 'partner' molecule from the boronate moiety to the oxime during reduction. However, attempts to obtain direct remote asymmetric induction in the reduction of homochiral β-oximino boronate methyl ethers 3 and 4 to the corresponding amines produced zero, with for example BH3-THF complex, up to 28% ee with an Et3N-BH3-THF mixture (after oxidative boronate ester cleavage).
- Sailes, Helen E.,Watts, John P.,Whiting, Andrew
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p. 3362 - 3374
(2007/10/03)
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- Synthesis, X-ray crystal-structure analysis, and NMR studies of (η3- allyl)palladium(II) complexes containing a novel dihydro(phosphinoaryl)oxazine ligand: Application in palladium-catalyzed asymmetric synthesis
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The novel chiral P,N-ligand 2-[2-(diphenylphosphino)phenyl]-5,6-dihydro- 4-phenyl-4H-1,3-oxazine (4) was synthesized. The corresponding {dihydro[(phosphino-κP)aryl]oxazine-κN} (η3-diphenylallyl)palladium(II) hexafluorophosphate 5 and the analogous [Pd(η3-1,3-dimethylallyl)] complex 6 were investigated by X-ray analysis and 1D- and 2D-NMR spectroscopy. The complex 5 exists as 'exo'-syn-syn isomer in the solid state (Fig. 1). In solution, the same isomer exceeds with 90%. The X-ray crystal structure of 6 reveals that the dihydro(phosphinoaryl)oxazine ligand coordinates in a pseudo-enantiomeric conformation compared with that of 5 (Fig. 3). A syn-anti arrangement of the allyl substituents of 6 is favored in the solid state. 1H-NMR Spectroscopic investigations suggest that the auxiliary 6 adopts two conformations. This conformational instability together with 'exo'/'endo' and syn/anti isomerization leads to the formation of 6 isomers (Fig. 4). The asymmetric allylic substitution reaction of 1,3-diphenylallyl acetate with dimethyl malonate in the presence of 4 proceeds with a selectivity of 99% ee. The ee induced by 4 in the catalytic allylic substitution of 1-methylbut-2- enyl acetate is moderate (54%).
- Liu, Shuangying,Mueller, Juergen F. K.,Neuburger, Markus,Schaffner, Silvia,Zehnder, Margareta
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p. 1256 - 1267
(2007/10/03)
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- Oxazolidinones as alpha 1A receptor antagonists
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This invention is directed to oxazolidinone compounds which are selective antagonists for human alpha 1A receptors. This invention is also related to uses of these compounds for lowering intraocular pressure, inhibiting cholesterol synthesis, relaxing lower urinary tract tissue, the treatment of benign prostatic hyperplasia, impotency, cardiac arrhythmia and for the treatment of any disease where the antagonism of the alpha 1A receptor may be useful. The invention further provides a pharmaceutical composition comprising a therapeutically effective amount of the above-defined compounds and a pharmaceutically acceptable carrier.
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- (1′S,4S)-2-Aryl-4-(1′-hydroxybenzyl)-4,5-dihydro-oxazole as a useful chiral auxiliary for the synthesis of β-amino acids and β-lactams in a highly stereoselective manner
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(1′5,45)-2-Aryl-4-(1′-hydroxybenzyl)-4,5-dihydrooxazole prepared from (1S,2S)-2-amino-l-phenylpropane-l,3-diol has been found to be a useful chiral auxiliary for the stereoselective synthesis of β-lactams and β-amino acids in the reaction of imine-ester enolate condensation or 1,4-addition of lithium amides to α,β-unsaturated esters.
- Shimizu, Makoto,Maruyama, Shingo,Suzuki, Yasuhiro,Fujisawa, Tamotsu
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p. 1883 - 1889
(2007/10/03)
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- Regiospecific Opening of Oxetanes with Trimethylsilyl Cyanide - Zinc Iodide. A General Approach to γ-Amino Alcohols.
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Trimethylsilyl ethers of γ-hydroxy isonitriles were formed regiospecifically in the opening of oxetanes with trimethylsilyl cyanide - zinc iodide.Deprotection and hydrolysis of the initially formed ring cleavage products gave γ-amino alcohols.
- Gassman, Paul G.,Haberman, Leonard M.
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p. 4971 - 4974
(2007/10/02)
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- ADDITION OF NITRILES TO OXETANES
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The reaction of oxetanes with acrylonitrile and benzonitrile in the presence of concentrated sulfuric acid leads to the formation of the corresponding 5,6-dihydro-1,3-oxazines.
- Pavel', T. M.
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p. 157 - 159
(2007/10/02)
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- Synthesis via Isoxazolines, 5. - 1,3-Asymmetric Induction in the reduction of 3,5-Disubstituted 2-Isoxazolines; Diastereoselective Synthesis and Configurational Assignment of γ-Amino Alcohols
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The cycloaddition of nitrile oxides to alkenes, followed by reduction of the ensuing 2-isoxazolines 3, yields γ-amino alcohols 4 in a regioselective manner.The stereoselectivity of the reduction step is examined; it is highest with LiAlH4 as the reducing agent. 1,3-Asymmetric induction by isoxazoline ring substituents leads to β-4:α-4 ratios of ca. 85:15 for 5-methyl and ca. 95:5 for 5-phenyl. (CH3)2S-BH3, less selectively, furnishes 60:40, Na-Hg and Na/ethanol reduction give rise to 40:60 diastereomer mixtures.From these, two amino alcohols of the α-series are isolated. 3a is reduced by NaBH3CN to give cis/trans-isoxazolines 11. - The relative configurations of β- and α-4 and, consequently, the steric course of these reductions, are established by 1H- and 13C-NMR studies of 4 as well as of cyclic derivatives (azetidine 7, tetrahydro-1,3-oxazine 10).In addition, conformations of the free amino alcohols 4 are suggested on the basis of 13C-NMR data.
- Jaeger, Volker,Buss, Volker
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p. 101 - 121
(2007/10/02)
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