cas 63701-55-3, R(+)-BACLOFEN HYDROCHLORIDE

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Polysulfonate supported chiral diamine-nickel catalysts: Synthesis and applications
A series of chiral polysulfonate cyclohexyldiamine-Ni(II) catalysts were prepared via sulfur (VI) fluoride exchange click-reactions. The catalysts exhibited good catalytic activity and enantioselectivity in the Michael addition of malonates to nitroalkene
Zhou, Jing-xuan,Zhu, Dong-yu,Chen, Jie,Zhang, Xue-jing,Yan, Ming,Chan, Albert S.C.
(2021/01/25)

COCRYSTALS OF (R)-BACLOFEN
The invention relates to novel cocrystals of (R)-Baclofen and processes for preparation thereof, and in particular to cocrystals of (R)-Baclofen with cinnamic acid, benzoic acid, salicylic acid and ferulic acid. It also refers to pharmaceutical compositions containing said cocrystals and to a use of said cocrystals or pharmaceutical compositions for the treatment of a disease or disorder selected from spasticity due to multiple sclerosis, spinal cord injury or cerebral palsy, and alcoholism.
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(2020/07/21)

Synthesis of Nonracemic Tetrazole GABA Analogs
Nonracemic 3-substituted 4-(1H-tetrazol-1-yl)butanoic acids, analogs of the neurotropic drugs phenibut, tolibut, and baclofen, were synthesized by a three-component reaction of the R-isomers of the corresponding amino acids, triethyl orthoformate, and sod
Reznikov,Ostrovskii,Klimochkin, Yu. N.
p. 1715 - 1721
(2019/02/14)

Highly Enantioselective Synthesis of Chiral γ-Lactams by Rh-Catalyzed Asymmetric Hydrogenation
A Rh/bisphosphine-thiourea (ZhaoPhos) catalytic system has been identified for the straightforward asymmetric synthesis of chiral γ-lactams. A variety of NH free α,β-unsaturated lactams bearing a β-aryl or β-alkyl substituent were smoothly hydrogenated to
Lang, Qiwei,Gu, Guoxian,Cheng, Yaoti,Yin, Qin,Zhang, Xumu
p. 4824 - 4828
(2018/06/08)

Enantioselective conjugate hydrocyanation of α,β-unsaturated N-acylpyrroles catalyzed by chiral lithium(I) phosphoryl phenoxide
Enantioselective conjugate hydrocyanation of α,β-unsaturated N-acylpyrroles with the combined use of Me3SiCN, LiCN, and HCN has been developed in the presence of a chiral lithium(I) phosphoryl phenoxide catalyst. This reaction is useful for a v
Hatano, Manabu,Yamakawa, Katsuya,Ishihara, Kazuaki
p. 6686 - 6690
(2017/11/09)

Squaramide-Catalyzed Michael Addition as a Key Step for the Direct Synthesis of GABAergic Drugs
Enantioselective organocatalytic Michael additions serve as the key step in syntheses of chiral drugs based on γ-aminobutyric acid. The applicability of various squaramide catalysts for these Michael-type reactions has been assessed. Very good results in
Veverková, Eva,Bilka, Stanislav,Baran, Rastislav,?ebesta, Radovan
p. 1474 - 1482
(2016/05/24)

A synthetic γ-amino butyric acid kind of chiral the method for preparing the compound of
The invention discloses a method for synthesizing a gamma-aminobutyric acid chiral compound. The method comprises the following steps of: adding nitroolefin and malonate to a solvent in the presence of a catalyst A and an additive; carrying out conjugate
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(2017/03/17)

Development of Bifunctional Thiourea Organocatalysts Derived from a Chloramphenicol Base Scaffold and their Use in the Enantioselective Alcoholysis of meso Cyclic Anhydrides
The synthesis of new chloramphenicol-base-derived thiourea organocatalysts, (1S,2R)-12 a–f and (1R,2R)-15 a–c, and their use in the enantioselective alcoholysis of meso-anhydrides are described. In particular, hemiesters afforded excellent enantioselectivities if low loadings of (1S,2R)-12 a–f were used. Almost no enantioselectivities were achieved with the use of (1R,2R)-15 a–c. This technique was used to synthesize (R)-(?)-baclofen.
Yan, Lin-Jie,Wang, Hai-Feng,Chen, Wen-Xue,Tao, Yuan,Jin, Kai-Jun,Chen, Fen-Er
p. 2249 - 2253
(2016/07/19)

Opposite enantioselectivity in the bioreduction of (Z)-β-aryl-β-cyanoacrylates mediated by the tryptophan 116 mutants of old yellow enzyme 1: Synthetic approach to (R)- and (S)-β-aryl-γ-lactams
The Trp 116 mutants of Old Yellow Enzyme 1 that catalyse the reduction of (Z)-β-aryl-β-cyanoacrylates give the opposite enantioselectivity according to the nature of the amino acid in position 116. Small amino acids (e.g., alanine) make the substrate bind
Brenna, Elisabetta,Crotti, Michele,Gatti, Francesco G.,Monti, Daniela,Parmeggiani, Fabio,Powell, Robert W.,Santangelo, Sara,Stewart, Jon D.
p. 1849 - 1860
(2015/06/02)

Efficient synthesis of β-aryl-γ-lactams and their resolution with (S)-Naproxen: Preparation of (R)- and (S)-Baclofen
An efficient synthesis of enantiomerically-pure β-aryl-γ-lactams is described. The principal feature of this synthesis is the practical resolution of β-aryl-γ-lactams with (S)-Naproxen. The procedure is based on the Michael addition of nitromethane to benzylidenemalonates, which was easily obtained, followed by the reduction of the γ-nitroester in the presence of Raney nickel and the subsequent saponification/decarboxylation reaction. The utility of this methodology was highlighted by the preparation of enantiomerically-pure (R)- and (S)-Baclofen hydrochloride.
Montoya-Balbás, Iris J.,Valentín-Guevara, Berenice,López-Mendoza, Estefanía,Linzaga-Elizalde, Irma,Ordo?ez, Mario,Román-Bravo, Perla
p. 22028 - 22043
(2016/01/25)

Highly Enantioselective Michael Addition of Nitroalkanes to Enones and Its Application in Syntheses of (R)-Baclofen and (R)-Phenibut
A highly enantioselective Michael addition of nitroalkanes to α,β-unsaturated ketones was developed. In the presence of a chiral primary amine-thiourea catalyst based on dehydroabietic amine, γ-nitro ketones were obtained with excellent enantioselectiviti
Guo, Xing-Tao,Shen, Jie,Sha, Feng,Wu, Xin-Yan
p. 2063 - 2072
(2015/07/15)

Regio- and enantioselective palladium-catalyzed allylic alkylation of nitromethane with monosubstituted allyl substrates: Synthesis of (R)-rolipram and (R)-baclofen
The Pd-catalyzed asymmetric allylic alkylation (AAA) reaction of nitromethane with monosubstituted allyl substrates was realized for the first time to provide corresponding products in high yields with excellent regio- and enantioselectivities. The protocol was applied to the enantioselective synthesis of (R)-baclofen and (R)-rolipram.
Yang, Xiao-Fei,Ding, Chang-Hua,Li, Xiao-Hui,Huang, Jian-Qiang,Hou, Xue-Long,Dai, Li-Xin,Wang, Pin-Jie
p. 8980 - 8985,6
(2012/12/12)

Regio- and enantioselective palladium-catalyzed allylic alkylation of nitromethane with monosubstituted allyl substrates: Synthesis of (R)-rolipram and (R)-baclofen
The Pd-catalyzed asymmetric allylic alkylation (AAA) reaction of nitromethane with monosubstituted allyl substrates was realized for the first time to provide corresponding products in high yields with excellent regio- and enantioselectivities. The protocol was applied to the enantioselective synthesis of (R)-baclofen and (R)-rolipram.
Yang, Xiao-Fei,Ding, Chang-Hua,Li, Xiao-Hui,Huang, Jian-Qiang,Hou, Xue-Long,Dai, Li-Xin,Wang, Pin-Jie
p. 8980 - 8985
(2013/01/15)

Asymmetric synthesis of β-substituted γ-lactams via rhodium/diene-catalyzed 1,4-additions: Application to the synthesis of (R)-baclofen and (R)-rolipram
An efficient rhodium/diene-catalyzed asymmetric addition of arylboronic acids to α,β-unsaturated γ-lactams has been developed. The power of this methodology is further demonstrated by the concise synthesis of (R)-baclofen and (R)-rolipram.
Shao, Cheng,Yu, Hong-Jie,Wu, Nuo-Yi,Tian, Ping,Wang, Rui,Feng, Chen-Guo,Lin, Guo-Qiang
p. 788 - 791
(2011/04/16)

METHOD OF PRODUCING PURIFIED OPTICALLY ACTIVE 4-AMINO-3-(SUBSTITUTED PHENYL)BUTANOIC ACID COMPOUND
A method of producing a purified optically active 4-amino-3-(substituted phenyl)butanoic acid compound which is characterized by comprising a step of making a crude optically active 4-amino-3-(substituted phenyl)butanoic acid compound contact an organic acid in the presence of water.
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(2011/04/18)

OPTICALLY ACTIVE 4-AMINO-3-(4-CHLOROPHENYL)BUTANOIC ACID
Provided is a new crystal A of optically active 4-amino-3-(4-chlorophenyl)butanoic acid which is far better in stability, and a process for producing the crystal and a process for producing the crystal A comprising a step of heating the following crystal B in water having a pH of 3 to 9: crystal A: a crystal of optically active 4-amino-3-(4-chlorophenyl)butanoic acid which has diffraction peaks within the range of a diffraction angle 2θ of 8.7 to 9.4°, within that of 2θ of 12.2 to 12.8°, and within that of 2θ of 24.8 to 25.4° in a powder X-ray diffraction measurement of the crystal by use of the Cu—Kα wavelength; and crystal B: a crystal of optically active 4-amino-3-(4-chlorophenyl)butanoic acid which has diffraction peaks within the range of a diffraction angle 2θ of 20.8 to 21.4°, within that of 2θ of 26.7 to 27.3°, and within that of 2θ of 29.7 to 30.3° in a powder X-ray diffraction measurement of the crystal by use of the Cu—Kα wavelength.
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(2011/07/06)

Biscinchona alkaloids as highly efficient bifunctional organocatalysts for the asymmetric conjugate addition of malonates to nitroalkenes at ambient temperature
The novel bifunctional bisalkaloids have been developed as highly efficient catalysts for the asymmetric conjugate addition of 1,3-dicarbonyl compounds to nitroalkenes with low catalyst loading (1 mol %) at ambient temperature, providing the products with
Li, Fei,Li, Ying-Zi,Jia, Zhen-Shan,Xu, Ming-Hua,Tian, Ping,Lin, Guo-Qiang
p. 10186 - 10194
(2012/01/03)

Method of Producing Optically Active 4-Amino-3-Substituted Phenylbutanoic Acid
The present invention provides a method of producing a compound (IIa) or a compound (IIb), provides a method of producing a compound (IIIa) or a compound (IIIb), provides a method of producing a compound (Va) or its salt or a compound (Vb) or its salt, provides a method of producing a compound (IIIa) or a compound (IIIb), further, provides a method of producing a compound (Va) or its salt or a compound (Vb) or its salt including these production methods.
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(2009/06/27)

An efficient synthesis of (R)- and (S)-baclofen via desymmetrization
A short and highly enantioselective synthesis of both enantiomers of GABA agonist baclofen in four steps with total yields of 32.8% [for (S)-isomer] and 35.1% [for (R)-isomer] is reported. The key step involved desymmetrization of cyclic anhydride with mo
Ji, Lei,Ma, Yuheng,Li, Jin,Zhang, Liangren,Zhang, Lihe
scheme or table
p. 6166 - 6168
(2009/12/26)

Rh-catalyzed asymmetric hydrogenation of γ-phthalimido-substituted α,β-unsaturated carboxylic acid esters: An efficient enantioselective synthesis of β-aryl-γ-amino acids (Organic Letters (2007) 9)
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Deng, Jun,Duan, Zheng-Chao,Huang, Jia-Di,Hu, Xiang-Ping,Wang, Dao-Yong,Yu, Sai-Bo,Xu, Xue-Feng,Zheng, Zhuo
supporting information; experimental part
p. 3379 - 3379
(2009/04/18)

Enantioselective synthesis of β-aryl-γ-amino acid derivatives via Cu-catalyzed asymmetric 1,4-reductions of γ-phthalimido-substituted α,β-unsaturated carboxylic acid esters
(Chemical Equation Presented) A series of chiral β-aryl-substituted γ-amino butyric acid derivatives were synthesized in good enantioselectivities via the Cu-catalyzed asymmetric conjugate reduction of γ-ph-thalimido-α,β-unsaturated carboxylic acid esters
Deng, Jun,Hu, Xiang-Ping,Huang, Jia-Di,Yu, Sai-Bo,Wang, Dao-Yong,Duan, Zheng-Chao,Zheng, Zhuo
p. 6022 - 6024
(2008/12/22)

Highly enantioselective organocatalytic conjugate addition of nitromethane to α,β-unsaturated aldehydes: Three-step synthesis of optically active baclofen
An efficient, organocatalytic, highly enantioselective, conjugate addition reaction of nitromethane with α,β-unsaturated aldehydes has been developed. The process serves as the key step for a practical 3-step synthesis of chiral baclofen, an antispastic drug.
Zu, Liansuo,Xie, Hexin,Li, Hao,Wang, Jian,Wang, Wei
p. 2660 - 2664
(2008/09/19)

The amino thiourea-catalyzed asymmetric nucleophilic reactions
Bifunctional amino thiourea-catalyzed asymmetric additions of several nucleophiles into electron-deficient unsaturated compounds such as nitroolefins, α,β-unsaturated imides, imines, and azodicarboxylates are described. We discovered that bifunctional thi
Takemoto, Yoshiji,Miyabe, Hideto
p. 269 - 275
(2008/02/06)

Rh-catalyzed asymmetric hydrogenation of γ-phthalimido-substituted α,β-unsaturated carboxylic acid esters: An efficient enantioselective synthesis of β-aryl-γ-amino acids
(Chemical Equation Presented) A series of chiral β-aryl-γ-amino acid ester derivatives were synthesized in high enantioselectivities (93-97% ee) via the Rh-catalyzed asymmetric hydrogenation of γ-phthalimido-α, β-unsaturated carboxylic acid esters using highly modular chiral BoPhoz-type phosphine-aminophosphine ligands. The method has been applied successfully to the synthesis of several chiral pharmaceuticals including (R)-baclofen and (R)-rolipram with high enantioselectivities.
Deng, Jun,Duan, Zheng-Chao,Huang, Jia-Di,Hu, Xiang-Ping,Wang, Dao-Yong,Yu, Sai-Bo,Xu, Xue-Feng,Zheng, Zhuo
p. 4825 - 4828
(2008/03/15)

Asymmetrie synthesis of (R)-(-)-baclofen via asymmetric dihydroxylation
A short and efficient asymmetric synthesis of (R)-(-)-baclofen, a selective GABAB agonist has been described with an overall yield of 14% and 85% ee. The Os-catalyzed Sharpless asymmetric dihydroxylation of a,β-unsaturated olefin constitutes the key step in introducing stereogenic centers into the molecule.
Thakur,Paraskar,Sudalai
p. 326 - 330
(2008/02/09)

Co-catalyzed reductive cyclization of azido and cyano substituted α,β-unsaturated esters with NaBH4: enantioselective synthesis of (R)-baclofen and (R)-rolipram
Sodium borohydride in combination with a catalytic amount of CoCl2 has been found to be an excellent catalytic system in reductive cyclizations of suitably substituted azido and cyano groups of α,β-unsaturated esters to afford γ and δ-lactams in high yields. The process has been demonstrated for the enantioselective synthesis of (R)-baclofen, (R)-rolipram, and (R)-4-fluorophenylpiperidinone, a key intermediate for (-)-paroxetine.
Paraskar, Abhimanyu S.,Sudalai, Arumugam
p. 4907 - 4916
(2007/10/03)

Asymmetric synthesis of β-substituted γ-lactams employing the samp-/ramp-hydrazone methodology. Application to the synthesis of (R-(-)-baclofen
A short and efficient asymmetric synthesis of β-substituted γ-lactams is described. Key steps are the α-alkylation of aldehyde SAMP-hydrazones with alkyl bromoacetates, their MMPP mediated conversion to the corresponding nitriles and a reductive cyclization with Raney Ni or Ni boride to the title pyrrolidin-2-ones. The β-substituted γ-lactams are obtained in three steps, good overall yields (27-78%) and excellent enantiomeric excesses (ee=93-99%). The applicability of this procedure for the asymmetric synthesis of GABAs (γ-aminobutyric acids) is demonstrated for (R-(-)-baclofen hydrochloride, which is obtained in 4 steps 55% yield and 94% ee.
Enders, Dieter,Niemier, Oliver
p. 385 - 403
(2007/10/03)

Enantio- and diastereoselective michael reaction of 1,3-dicarbonyl compounds to nitroolefins catalyzed by a bifunctional thiourea
We synthesized a new class of bifunctional catalysts bearing a thiourea moiety and an amino group on a chiral scaffold. Among them, thiourea 1e bearing 3,5-bis(trifluoromethyl)benzene and dimethylamino groups was revealed to be highly efficient for the as
Okino, Tomotaka,Hoashi, Yasutaka,Furukawa, Tomihiro,Xu, Xuenong,Takemoto, Yoshiji
p. 119 - 125
(2007/10/03)

Synthesis of both enantiomers of baclofen using (R)- and (S)-N-phenylpantolactam as chiral auxiliaries
Esterification of racemic 4-nitro-3-(4-chlorophenyl)butanoic acid with (R)- or (S)-N-phenylpantolactam as the chiral auxiliary allowed us to obtain the (3R,3′R)- or (3S,3′S)-nitro esters with >98:2 dr after column chromatography. Hydrolysis of the resulti
Camps, Pelayo,Munoz-Torrero, Diego,Sanchez, Laura
p. 2039 - 2044
(2007/10/03)

Recoverable resin-supported pyridylamide ligand for microwave-accelerated molybdenum-catalyzed asymmetric allylic alkylations: Enantioselective synthesis of baclofen
(Matrix presented) The syntheses of a series of 4-monosubstituted pyridylamides and a resin-supported pyridylamide are described. The ligands were evaluated in the microwave-accelerated molybdenum-catalyzed asymmetric allylic alkylation. The reaction affo
Belda, Oscar,Lundgren, Stina,Moberg, Christina
p. 2275 - 2278
(2007/10/03)

Enantioselective synthesis of (R)-(-)-baclofen via Ru(II)-BINAP catalyzed asymmetric hydrogenation
A short and efficient enantioselective synthesis of (R)-(-)-baclofen, a selective GABAB agonist has been described with an overall yield of 26% and 90% ee. Ru(II)-(S)-BINAP catalyzed asymmetric hydrogenations of C=C and C=O groups constitute the key steps in introducing stereogenic centers into the molecule.
Thakur, Vinay V.,Nikalje, Milind D.,Sudalai
p. 581 - 586
(2007/10/03)

Enantioselective synthesis of (R)-(-)-baclofen using Fischer-type carbene anions
The antispastic drug (R)-(-)-baclofen has been synthesized enantioselectively using a diastereoselective Michael addition reaction of the conjugate base of an enantiopure Fischer-type amino carbene to p-chloro-nitrostyrene. Copyright (C) 2000 Elsevier Science Ltd.
Licandro, Emanuela,Maiorana, Stefano,Baldoli, Clara,Capella, Laura,Perdicchia, Dario
p. 975 - 980
(2007/10/03)

Enantioselective Michael addition of nitromethane to α,β-enones catalyzed by chiral quaternary ammonium salts. A simple synthesis of (R)-baclofen
(equation presented) R/S = 85/15, 97.5/2 after recryst. Enantioselective Michael addition of nitromethane to an α,β-enone is a key step in the synthesis of (R)-baclofen.
Corey,Zhang, Fu-Yao
p. 4257 - 4258
(2007/10/03)

Enantioselective synthesis of 4-substituted 2-pyrrolidinones by site- selective C-H insertion of α-methoxycarbonyl-α-diazoacetanilides catalyzed by dirhodium(II) tetrakis[N-phthaloyl-(S)-tert-leucinate]
Site- and enantioselective intramolecular C-H insertion of α- methoxycarbonyl-α-diazoacetamides has been achieved by exploiting a p- nitrophenyl group as the N-substituent and dirhodium(II) tetrakis[N- phthaloyl-(S)-tert-leucinate] as catalyst, leading to the formation of 4 substituted 2-pyrrolidinone derivatives of up to 82% ee. The efficiency of the present protocol has been verified well by a short-step synthesis of (R)- (-)-baclofen.
Anada, Masahiro,Hashimoto, Shun-Ichi
p. 79 - 82
(2007/10/03)

A chemoenzymatic strategy for the synthesis of enantiopure (R)-(-)-baclofen
A seven-step enantioselective synthesis of (R)-(-)-baclofen 1 is described. The strategy developed involved as a key step, a microbiologically mediated Baeyer Villiger oxidation of the prochiral 3-(4'-chlorobenzyl)-cyclobutanone 3 which led to the optically pure (R)-(-)-4 lactone. This was further transformed throughout chemospecific reactions into the target molecule (R)-(-)-1.
Mazzini, Claudio,Lebreton, Jacques,Alphand, Veronique,Furstoss, Roland
p. 1195 - 1196
(2007/10/03)

Stereospecific synthesis of (R)- and (S)-Baclofen and (R)- and (S)- PCPGABA [4-amino-2-(4-chlorophenyl)butyric acid] via (R)- and (S)-3-(4- chlorophenyl)pyrrolidines
(R)- and (S)-baclofen and (R)- and (S)-PCPGABA [4-amino-2-(4- chlorophenyl)butyric acid] were stereospecifically synthesized via (R)- and (S)-3-(4-chlorophenyl)pyrrolidines, starting from trans-4-hydroxy-L-proline. The syntheses involve two key operations
Yoshifuji,Kaname
p. 1302 - 1306
(2007/10/02)

Synthesis of Homochiral R-Baclofen from S-Glutamic Acid
A streoselective synthesis of R-Baclofen is presented starting from S-pyroglutamic acid derivative 3.The key steps are the 1,4-conjugate addition of Grignard cuprate (p-ClPh)2CuMgCl to 3 and Barton-Decarboxylation of 6e to 7e.
Herdeis, C.,Hubmann, H. P.
p. 1213 - 1221
(2007/10/02)

Chemoenzymatic synthesis of both enantiomers of baclofen
Both enantiomers of baclofen have been synthesized in five steps from 4-chlorocinnamic acid. The key step is the highly stereoselective enzymatic hydrolysis of dimethyl 3-(4-chlorophenyl)glutarate by chymotrypsin.
Chenevert, Robert,Desjardins, Michel
p. 4249 - 4250
(2007/10/02)