Chiral Quaternary Ammonium Salt Derived from Dehydroabietylamine: Synthesis and Application to Alkynylation of Isatin Derivatives Catalyzed by Silver

Abietic acid and its derivatives have broadly been used in fine chemicals and are renewable resources. Its inherent chiral rigid tricyclic phenanthrene skeleton is unique. Its utilities in asymmetric catalysis remain to be explored. A series new amide-type chiral quaternary ammoniums bearing dehydroabietylamine were designed, and prepared by two convenient steps. Acylation of dehydroabietylamine with bromoacetyl chloride afforded amide holding bromoacetyl group in higher yields using triethyl amine as base. Subsequent quaternization reaction gave the desired amide-type chiral quaternary ammoniums. The new chiral quaternary ammoniums can be used as phase-transfer catalyst (PTC) for the transition metal-catalysed alkynylation of isatin derivatives.

Synthesis and Characterization of Macrocyclic Chiral Tröger’s Base Phenhomazine Candidates as Anticancer Agent

1,4,7,10-Tetraoxa[10](2,8)trögerophane 5 was synthesized from its corresponding precursors. Heating of 2 with p-nitrophenoxide afforded bis(p-nitrophenyl)ether 3, which was treated with hydrazine hydrate to give bis(p-aminophenyl)ether 4. Treatment of 4 with paraformaldehyde and triflouroacetic anhydride gave trögerophane 5. Reaction of 5 with trifluroacetic anhydride afforded phenhomazine derivative 6, which was treated with potassium carbonate to afford tetrahydrophenhomazine 7. Finally, reaction of 7 with phenacylchloride, bromoacetic acid, or ethyl bromoacetate in the presence of triethyl amine under reflux, afforded the corresponding macrocyclic compounds 8, 9 and 10, respectively. The synthesized trögerophane,precursors and its newly synthesized phenhomazines derivatives were screened for anticancer activity. Results revealed that 1,4,7,10-tetraoxa[10](2,8)trögerophane had a promising selectivity towards colon cancer cell line with an IC50 of 92.7 µg/ml.

Nickel Nanoparticles Immobilized on a Porous Triazine-Thiourea-Sulfonamide as an Efficient Heterogeneous Catalyst for Reduction of Carbonyl Compounds

In order to investigate the role of silica template, polymers and nickel nanoparticles on the reduction of aldehydes/ketones, a novel porous triazine-thiourea-sulfonamide polymeric organic support (TTSA) was prepared via in-situ polymerization of melamine (1,3,5-triazine-2,4,6-triamine), thiourea and benzene-1,3-disulfonyl chloride in the presence of silica nanoparticles as a template led to the synthesize silica TTSA nanocomposite. Next, after removal of the template, the nanocomposite was transformed into mesoporous poly triazine-thiourea-sulfonamide. Ni nanoparticles (Ni NPs) were then decorated on the designed mesoporous polymer support and the resulting TTSA@Ni NPs nanospheres were employed as heterogeneous catalyst in the construction of alchohols from reduction of aldehydes/ketones using formic acid/triethyl amine as a reducing agent in water as solvent. The catalyst is low-cost, non-toxic, and can be reused for several catalytic cycles without decreasing the activity.

4,4'-Bipyridine-based Ni(II)-metallogel for Fabricating the Electronic Device of Photo-responsive Schottky Barrier Diode

A functionally advanced Ni(II)-metallogel (Ni-D-TA) has been derived through the sonication of Nickel(II) chloride hexahydrate and 4,4'-Dipyridyl, and triethyl amine in N,N-dimethyl formamide solvent at room temperature under ambient conditions....

Stability Indicating Method for known and unknown impurities profiling for Vildagliptin in Vildagliptin Tablet

Background: Vildagliptin is a drug for the treatment of diabetes. DPP-IV inhibitor represents a new class of oral antihyperglycemic agents to treat patients with type 2 diabetes. Several RP-HPLC method reported for determination of Vildagliptin alone. However, it was noticed that no stability indicating method is available in any Pharmacopeia (USP/BP/EP/JP) or in any literature for quantification of known and unknown impurities profiling for Vildagliptin in Vildagliptin tablets. Objective: The aim of this study to develop a simple, sensitive, rugged, robust and specific novel gradient stability indicating RP-HPLC method for quantitative determination of known, unknown impurities and degradants of Vildagliptin in Vildagliptin Tablets. Methods: Chromatographic separation has been achieved on Hypersil ODS column (250 x 4.6) mm, 5 μm with mobile phase consisting mixture of Perchloric acid Buffer, methanol, acetonitrile and Triethyl amine delivered at flow rate of 1.0 mL minute-1 and the detection wavelength 210 nm. The developed method was validated as per ICH guidelines. Results: Vildagliptin was found degraded significantly under oxidative and alkaline stress condition. The degradation products were well resolved from Vildagliptin and its impurities. Analytical Method found Linear, accurate and precise from LOQ (Limit of Quantification) level to 150 % of impurity specification limit (0.5 %). Conclusion: The method found sensitive, rapid and accurate quantification of known, unknown impurities and degradants. The peak purity results confirmed that the Vildagliptin peak was homogeneous and pure in all stress samples, thus proving the stability indicating nature of the method.

Synthesis and Properties of N1-(indan-5-yl)amidrazones Incorporating Piperazines and Related Congeners

: A selected set of new N1-(indan-5-yl)amidrazones 4a-p, encompassing piperazines or related amines, has been prepared via interaction of the hydrazonoyl chloride 3 (derived from 5-aminoindane) with the appropriate sec-cyclic amine in the presence of triethyl amine. Their suggested structures are supported by IR, 1H NMR, 13C NMR, high resolution MS (ESI) spectral data and further confirmed by single-crystal X-ray crystallography for 4k. These novel compounds were screened for their antitumor activity against breast cancer cells (MCF7 and T47D); amongst all of them, only compound 4o, incorporating N-(pyrimidin-2-yl)piperazine, was fairly active with IC50 values of 69 µM and 61 µM, respectively.

Method development and validation of Ifetroban by RP-UPLC

The purpose of this work is to develop and validate reverse phase Ultra performance liquid chromatography (UPLC) method for the rapid and precise determination of ifetroban sodium in its pure form and in formulations. A simple, specific, accurate, precise isocratic UPLC method for analysis of Ifetroban sodium was developed and validated using a Phenomenex C18 column (50 mm x 3.0 mm, 3µ) as the stationary phase, in conjunction using Triethyl amine buffer: methanol in the proportion of 25:75 with a flow rate of 1.0 mL/min, run time is 3 min and UV detector is used at 235 nm wavelength. The developed UPLC technique was found to be rapid as the retention time was 0.56 minutes for Ifetroban peak to elute. The developed UPLC technique was validated as per the ICH guidelines for specificity, linearity, accuracy, precision, robustness and found to be satisfactory. Linearity was established in the concentration range 100-300 µg/mL with correlation coefficient of 0.998 and the equation obtained is y = 0.635x + 0.639.The percentage recovery is 100.41. The method is rugged and is trouble free and transferable. The study showed that the developed UPLC technique can be used for the estimation of drug purity, stability, solubility and with no interference of pharmaceutical excipients from the active pharmaceutical ingredient. The precision, accuracy, robustness results obtained enables rapid quantification of ifetroban for quantitative analysis.

Preparation of a new ionic liquid from cococnut oil for friction-reducing additive for lubricant

A new ionic liquid triethylammonium carboxylate [(C2H5)3NH][RCOO] (where R is fatty acid groups of coconut oil) was synthesized from fatty acid of coconut oil and triethyl amine. Graphene oxide (GO) was synthesized from graphite via modified Hummers method then was reduced to form reduced graphene oxide. The products were characterized and confirmed by FT-IR, XRD and NMR analysis. Friction-reducing additives was prepared from by dispersed reduced graphene oxide in [(C2H5)3NH][RCOO] (0.1%). Friction-reducing properties of materials were measured by GOST P56946-2016 (equivalent to ISO 13500:2008). The results show that using graphene and liquid triethylammonium hydrogen carboxylate lead to increase in the friction-reducing property of based oil in drilling fluid and mixture of them showed highest capacity of increasing the friction-reducing property of drilling fluid.