127931-16-2

Upstream product

• 35386-24-4 1-(2-Methoxyphenyl)piperazine 
• 61249-00-1 (S)-(1-naphthyl) glycidyl ether 
• 67843-74-7 (S)-epichlorohydrin 
• 90-15-3 α-naphthol 
• 51594-55-9 (R)-(-)-epichlorohydrin 
• 1621070-08-3 (S)-1-(2-methoxy-phenyl)-4-oxiranylmethyl-piperazine 
• 61248-78-0 (R)-3-(1-naphthyloxy)-1,2-propanediol 
• 57149-07-2 naftopidil 
• 766-51-8 2-Chloroanisole 
• 2461-42-9 3-(1-naphthyloxy)-1,2-epoxypropane 
• 90-04-0 2-methoxy-phenylamine 

Relevant academic research and scientific papers

Organocatalytic enantioselective synthesis of β-blockers: (S)-propranolol and (S)-naftopidil

An efficient enantioselective synthesis of β-adrenergic blockers (S)-propranolol and (S)-naftopidil with >98% ee using an l-proline-catalyzed α-aminoxylation of an aldehyde as a key step is described.

Conventional chiralpak ID vs. capillary chiralpak ID-3 amylose tris-(3-chlorophenylcarbamate)-based chiral stationary phase columns for the enantioselective HPLC separation of pharmaceutical racemates

A comparative enantioselective analysis using immobilized amylose tris-(3-chlorophenylcarbamate) as chiral stationary phase in conventional high-performance liquid chromatography (HPLC) with Chiralpak ID (4.6mm ID×250mm, 5μm silica gel) and micro-HPLC with Chiralpak ID-3 (0.30mm ID×150mm, 3μm silica gel) was conducted. Pharmaceutical racemates of 12 pharmacological classes, namely, α- and β-blockers, anti-inflammatory drugs, antifungal drugs, dopamine antagonists, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, diuretics, antihistaminics, anticancer drugs, and antiarrhythmic drugs were screened under normal phase conditions. The effect of an organic modifier on the analyte retentions and enantiomer recognition was investigated. Baseline separation was achieved for 1-acenaphthenol, carprofen, celiprolol, cizolirtine carbinol, miconazole, tebuconazole, 4-hydroxy-3-methoxymandelic acid, 1-indanol, 1-(2-chlorophenyl)ethanol, 1-phenyl-2-propanol, flavanone, 6-hydroxyflavanone, 4-bromogluthethimide, and pentobarbital on the 4.6mm ID packed with a 5μm silica column using conventional HPLC. Nonetheless, baseline separation was achieved for aminoglutethimide, naftopidil, and thalidomide on the 0.3mm ID packed with a 3μm silica capillary column. Chirality 26:677-682, 2014.

Silver nanoparticle-catalysed phenolysis of epoxides under neutral conditions: Scope and limitations of metal nanoparticles and applications towards drug synthesis

Chemo- and regio-selective epoxide phenolysis is reported for the first time under neutral condition catalysed by silver nanoparticles. Other metal nanoparticles (e.g., Au, Pd, Cu, In, and Ru) are less effective. The choice of solvent is critical with 2-propanol being the best followed by DEF. Amongst various stabilisers used (surfactants, PEGs, tetra-alkylammonium halides) the tetra-alkylammonium halides are found to be the most effective (TBAF > TBAB > TBACl > TBAI). The role of the silver nanoparticles is envisaged as synchronous mode epoxide-phenol dual activation via a cooperative network of coordination, anion-π interaction, and hydrogen bond. The silver nanoparticles are recovered and reused for five consecutive times. The reaction has been used for the synthesis of propranolol and naftopidil as a few representative cardiovascular drugs.

Asymmetric synthesis of propranolol, naftopidil and (R)-monobutyrin using a glycerol desymmetrization strategy

Herein, an approach for desymmetrization of glycerol by using a readily available camphorsulfonamide as a starting material is described. The strategy for asymmetric synthesis of (R)/(S)-propranolol, (R)/(S)-naftopidil and (R)-monobutyrin with spiroketal formation by desymmetrization was employed and Mitsunobu reaction was used for epoxide and ether formation. Steglich esterification and CAN (cerium ammonium nitrate) mediated ketal deprotection, were key steps in the synthesis. Regioselective ring opening of epoxide gave desired molecule with good overall yield and optical purity.

Zinc(II) perchlorate hexahydrate catalyzed opening of epoxide ring by amines: Applications to synthesis of (RS)/(R)-propranolols and (RS)/(R)/(S)-naftopidils

(Figure Presented) Commercially available zinc(II) Perchlorate hexahydrate [Zn(ClO4)2·6H2O] was found to be a new and highly efficient catalyst for opening of epoxide rings by amines affording 2-amino alcohols in high yields under solvent-free conditions and with excellent chemo-, regio-, and stereoselectivities. For unsymmetrical epoxides, the regioselectivity was influenced by the electronic and steric factors associated with the epoxides and the amines. A complementarity in the regioselectivity was observed during the reaction of styrene oxide with aromatic and aliphatic amines: aromatic amines provided amino alcohols from nucleophilic attack at the benzylic carbon as major products whereas aliphatic amines resulted in formation of the amino alcohols through reaction at the terminal carbon atom of the epoxide ring as the major/sole products. Reaction of aniline with various glycidic ethers gave the amino alcohols by regioselective nucleophilic attack at the terminal carbon atom of the epoxide ring as the only/major product. Zinc(II) Perchlorate hexahydrate was found to be the best catalyst compared to other metal Perchlorates. The counteranion modulated the catalytic property of the various Zn(II) compounds that followed the order Zn(ClO4) 2·6H2O Zn(BF4)2 ～ Zn(OTf)2 ZnI2 > ZnBr2 > ZnCl2 > Zn(OAc)2 > Zn(CO3)2 in parallelism with the acidic strength of the corresponding protic acids (except for TfOH). The applicability of the methodology was demonstrated by the synthesis of cardiovascular drugs propranolol and naftopidil as racemates and optically active enantiomers.

Hydrolytic kinetic resolution of α-naphthyl glycidyl ether: A practical access to highly enantioselective β-adrenergic blocking agents

Kinetic resolution of (±)-naphthyl glycidyl ether using 0.5 mol% (R,R)-salen Co(III)OAc and water (0.55 equiv) provided enantiomerically pure naphthyl glycidyl ether and 1-naphthylglycerol derivatives with high enantiomeric excess. Application of this approach to highly enantioenriched (S)-naftopidil and (S)-propranolol is described. Georg Thieme Verlag Stuttgart.

The first enantiomerically pure synthesis of (S)- And (R)-naftopidil utilizing hydrolytic kinetic resolution of (±)-(α-Naphthyl) glycidyl ether

Hydrolytic Kinetic Resolution (HKR) of (±)-(α-Naphthyl) glycidyl ether with (R,R)-salen Co(III) OAc complex provided enatiomerically pure (S)-naphthyl glycidyl ether and (R)-1-naphthyl glycerol; opening of the corresponding pure terminal epoxide with 1-(2-methoxyphenyl)piperizine gave the enantiomerically pure (S)- and (R)-Naftopidil.