Evaluation of direct analysis in real time mass spectrometry for onsite monitoring of batch slurry reactions

Batch slurry reactions are widely used in the industrial manufacturing of chemicals, pharmaceuticals, petrochemicals and polymers. However, onsite monitoring of batch slurry reactions is still not feasible in production plants due to the challenge in analyzing heterogeneous samples without complicated sample preparation procedures. In this study, direct analysis in real time mass spectrometry (DART-MS) has been evaluated for the onsite monitoring of a model batch slurry reaction. The results suggested that automation of the sampling process of DART-MS is important to achieve quantitative results. With a sampling technique of manual sample deposition on melting point capillaries followed by automatic sample introduction across the helium beam, relative standard deviation (RSD) of the protonated molecule signals from the reaction product of the model batch slurry reaction ranged from 6 to 30%. This RSD range is improved greatly over a sampling technique of manual sample deposition followed by manual sample introduction where the RSDs are up to 110%. Furthermore, with the semi-automated sampling approach, semi-quantitative analysis of slurry samples has been achieved. Better quantification is expected with a fully automated sampling approach.     

Synthesis of 4-(2-chloroethyl)-2,3-dihydro[1,4]oxazino[2,3-b]quinoline and 4-(2-chloroethyl)2,3-dihydropyrido[2,3-b][1,4]oxazine

The title compounds were synthesized from 3-[bis(2-hydroxyethyl)amino]quinolin-2(1H)-one 11a and 3-[bis(2-hydroxyethyl)amino]pyridin-2(1H)-one 18 respectively. The preparation involved a tandem chlorination/cyclization reaction.     

Regioselective synthesis of thiophene fused sultam derivatives via iodocyclization approach and their application towards triazole linker

An efficient regioselective synthesis of 4-iodo-2,3-disubstituted-2H-thieno[3,2-e][1,2]thiazine-1,1-dioxide derivatives via iodocyclization approach using iodine under mild reaction condition described herein. This coupling–iodocyclization strategy tolerated a variety of functional groups such as alkyl, cycloalkyl, phenyl producing the six-membered heterocyclic ring selectively. The resulting 4-iodo-2,3-disubstituted-2H-thieno[3,2-e][1,2]thiazine-1,1-dioxide was coupled with a variety of boronic acids (Suzuki coupling) and activated alkenes (Heck coupling). The iodo group was utilized for Sonogashira coupling followed by efficient transformation to azido precursor, which was used for the synthesis of various thieno-sultam linked with triazole.     

Metal catalyst-free direct α-iodination of ketones with molecular iodine

Ketones are directly converted to the corresponding α-iodoketones in good yields with molecular iodine under metal catalyst-free conditions. A significant difference in the reactivities was observed for aliphatic and aromatic ketones; whereas aliphatic ketones reacted smoothly at room temperature giving a mixture of 1-iodo, 3-iodo and 1,3-diiodoketones with predominant formation of the 3-iodo product, the α-iodination of aromatic ketones proceeded conveniently under heating to give good yields of α-iodo products.     

One‐Pot,Three‐Component Synthesis of Novel Spiro[3H‐indole‐3,2′‐thiazolidine]‐2,4′(1H)‐diones in an Ionic Liquid as a Reusable Reaction Media

A facile one‐pot, three‐component protocol for the synthesis of novel spiro[3H‐indole‐3,2′‐thiazolidine]‐2,4′(1H)‐diones by condensing 1H‐indole‐2,3‐diones, 4H‐1,2,4‐triazol‐4‐amine and 2‐sulfanylpropanoic acid in [bmim]PF₆ (1‐butyl‐3‐methyl‐1H‐imidazolium hexafluorophosphate) as a recyclable ionic‐liquid solvent gave good to excellent yields in the absence of any catalyst (Scheme 1 and Table 2). The advantages of this protocol over conventional methods are the mild reaction conditions, the high product yields, a shorter reaction time, as well as the eco‐friendly conditions.     

In vitro antiproliferative activity of glabridin derivatives and their in silico target identification

Abstract

Novel Mannich base derivatives of glabridin were synthesized and their antiproliferative activity were performed along with our previously reported glabridin-chalcone hybrids molecules (GCHMs) against various human cell lines MDA-MB-231 (breast adenocarcinoma), HEK-293 (embryonic kidney cell line), K562 (leukemia), MCF-7 (breast adenocarcinoma), HeLa (cervix adenocarcinoma), HepG2 (hepatocellular carcinoma) and WRL-68 (hepatic carcinoma). The result showed that the glabridin significantly reduced cell proliferation with IC₅₀ ranges from 3.67 to 58.30?µM against all the tested cell lines. The remarkable reduction in antiproliferative activity 2’,4’-dimethoxyglabridin and GCHMs compounds with phenolic OH groups protected by methoxy (OCH₃) groups suggested that the free OH groups are essential factor for the antiproliferative activity of glabridin and its derivatives. The Mannich base derivatives of glabridin showed moderate activity IC₅₀ (2.20–>95.78?µM). Furthermore, in silico target identification analysis revealed that AKT1, DECR1 and NOS1 are the potential targets for glabridin and their derivatives.     

Constraints on dark energy from the lookback time versus redshift test

We use lookback time versus redshift data from galaxy clusters (Capozziello et al., 2004 [9]) and passively evolving galaxies (Simon et al., 2005 [62]), and apply a Bayesian prior on the total age of the Universe based on WMAP measurements, to constrain dark energy cosmological model parameters. Current lookback time data provide interesting and moderately restrictive constraints on cosmological parameters. When used jointly with current baryon acoustic peak and Type Ia supernovae apparent magnitude versus redshift data, lookback time data tighten the constraints on parameters and favor slightly smaller values of the nonrelativistic matter energy density.     

A new palladium catalyzed protocol for atom-efficient cross-coupling reactions of triarylbismuths with aryl halides and triflates

A new palladium catalyzed protocol for an atom-efficient cross-coupling reaction of triarylbismuths with aryl halides and triflates has been described. The palladium catalytic system with Cs₂CO₃ base was found to be very efficient in DMA solvent to furnish excellent yields of cross-coupled functionalized biaryls in short reaction times.