Search

The methods for the separation of racemic compounds [(RS)-1-bromo-3-chloro-2-propanol, (RS)-1-bromo-3-chloropropan-2-yl acetate] into the corresponding enantiomers were tried to develop in high performance liquid chromatography in a single injection mode. In the case of HPLC, both the reversed (Phenomenex Lux 5u cellulose-1, Lux 5u cellulose-2, Lux 5u amylose-1) and normal phase (Chiralcel OJH, ODH, ADH) chiral columns were used for this purpose. HPLC methods could not resolute the desired enantiomers. However, phenoxy derivatives of (RS)-1-bromo-3-chloro-2-propanol and (RS)-1-bromo-3-chloropropan-2-yl acetate were separated by normal phase (ODH) column using a mobile phase consisting of n-hexane and isopropanol (80 : 20) at a flow rate of 0.5 mL/min (25°C) and detected at 254 nm. The method was validated for linearity, range, accuracy and precision. The developed method was applied for monitoring the progress of lipase catalyzed enantioselective synthesis of (S)-1-bromo-3-chloropropan-2-yl acetate from (RS)-1-bromo-3-chloro-2-propanol. All the analytes were synthesized chemically. Keywords: (RS)-1-bromo-3-chloro-2-propanol, (RS)-1-bromo-3-chloropropan-2-yl acetate, chiral HPLC, ODH column DOI: 10.1134/S1061934815010098, Aryloxypropanolamines are extensively used as precursors for the synthesis of a varieties of cardiovascular drugs used in the treatment of hypertension, myocardial infarction, arrhythmias, angina pectoris and ischemic heart disease [...]

Tyrosine kinase inhibitors are validated therapeutic agents against EGFR-mutated non-small cell lung cancer (NSCLC). However, the associated critical side effects of these agents are inevitable, demanding more specific and efficient targeting agents. Recently, we have developed and reported a non-covalent imidazo[1,2-a]quinoxaline-based EGFR inhibitor (6b), which showed promising inhibitory activity against the gefitinib-resistant H1975(L858R/T790M) lung cancer cell line. In the present study, we further explored the 6b compound in vivo by employing the A549-induced xenograft model in nude mice. The results indicate that the administration of the 6b compound significantly abolished the growth of the tumor in the A549 xenograft nude mice. Whereas the control mice bearing tumors displayed a declining trend in the survival curve, treatment with the 6b compound improved the survival profile of mice. Moreover, the histological examination showed the cancer cell cytotoxicity of the 6b compound was characterized by cytoplasmic destruction observed in the stained section of the tumor tissues of treated mice. The immunoblotting and qPCR results further signified that 6b inhibited EGFR in tissue samples and consequently altered the downstream pathways mediated by EGFR, leading to a reduction in cancer growth. Therefore, the in vivo findings were in corroboration with the in vitro results, suggesting that 6b possessed potential anticancer activity against EGFR-dependent lung cancer. 6b also exhibited good stability in human and mouse liver microsomes. [ABSTRACT FROM AUTHOR]

A new chemical and the first chemoenzymatic synthesis of β-adrenergic receptor blocking agent bunitrolol is reported in racemic (RS) and enantioenriched forms (R and S). The intermediates (R)- and (S)-1-chloro-3-(2-cyanophenoxy)propan-2-ol intermediates were synthesized from the corresponding racemic alcohol through enzymatic kinetic resolution. The commercial available lipases PS-C and CCL exhibited complementary enantioselectivity during transesterification of the racemic alcohol with vinyl acetate affording the (R)-alcohol along with (S)-acetate and the (S)-alcohol along with (R)-acetate, respectively, and represent an example of enzymatic switch for reversal of enantioselectivity. The effects of various reaction parameters, such as temperature, time, substrate and enzyme concentration, and reaction medium, on the activity and enantioselectivity were optimized. The (R)- and (S)-alcohols were converted into (S)-and and (R)-bunitrolol, respectively, by treatment with tert-butylamine. The (R)- and (S)-acetates, obtained enzymatically were deacetylated to the corresponding alcohol by chemical hydrolysis and further converted into (S)-and and (R)- bunitrolol by chemical means. This is the first chemoenzymatic synthesis of both of the enantiomers of the drug. (RS)-, (R)-, and (S)- Bunitrolol were also synthesized following the 'all chemical' routes from (RS)-, (R)-, and (S)-epichlorohydrin via the corresponding (RS)-, (S)-, and (R)-2-cyanoglycidyl ether and the (RS)-, (R)-, and (S)-1-chloro-3-(2-cyanophenoxy)propan-2-ol intermediates with improved overall yields and better enantiomeric excesses compared to the reported processes. [ABSTRACT FROM AUTHOR]

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(ll) 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. [ABSTRACT FROM AUTHOR]

Although new targeted therapies, such as ibrutinib and idelalisib, have made a large impact on non-Hodgkin's lymphoma (NHL) patients, the disease is often fatal because patients are initially resistant to these targeted therapies, or because they eventually develop resistance. New drugs and treatments are necessary for these patients. One attractive approach is to inhibit multiple parallel pathways that drive the growth of these hematologic tumors, possibly prolonging the duration of the response and reducing resistance. Early clinical trials have tested this approach by dosing two drugs in combination in NHL patients. We discovered a single molecule, MDVN1003 (1-(5-amino-2,3-dihydro-1H-inden-2-yl)-3-(8-fluoro-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine), that inhibits Bruton's tyrosine kinase and phosphatidylinositol-3-kinase δ , two proteins regulated by the B cell receptor that drive the growth of many NHLs. In this report, we show that this dual inhibitor prevents the activation of B cells and inhibits the phosphorylation of protein kinase B and extracellular signal-regulated kinase 1/2, two downstream mediators that are important for this process. Additionally, MDVN1003 induces cell death in a B cell lymphoma cell line but not in an irrelevant erythroblast cell line. Importantly, we found that this orally bioavailable dual inhibitor reduced tumor growth in a B cell lymphoma xenograft model more effectively than either ibrutinib or idelalisib. Taken together, these results suggest that dual inhibition of these two key pathways by a single molecule could be a viable approach for treatment of NHL patients., (Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.)

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.(6)H2O>>Zn(BF4)2 approximately 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.