Novel synthesis of 2-butyl-5-chloro-3H-imidazole-4-carbaldehyde:A key intermediate of Losartan

A novel method for synthesis of 2-butyl-5 -chloro-3H-imidazole-4-carbaldehyde 2, a key intermediate of Losartan was reported. The compound 2 was synthesized from starting material dimethyl malonate 6 and n-valeronitrile 8 by six steps with an overall yield of 40%. The key step including the reaction of compound 5 with POCl3/DMF followed by hydrolysis to give compound 2 with the yield of 68%.

Crystal and Molecular Structure Analysis in Knoevenagel Condensation Product of Substituted Napthofuran-2-Carbaldehydes

In the current study, two novel Knoevenagel condensation products of substituted napthofuran-2-carbaldehydes were designed, synthesized and characterized. In order to study the intermolecular interactions of title compounds, single crystals were grown by slow evaporation solution growth technique at room temperature and crystal structure has been determined by single crystal X-ray diffraction technique. Both the molecules crystallize in the monoclinic centrosymmetric space group P21/c with one molecule in the asymmetric unit. In compound [4] the molecules are connected via bifurcated C-H···O=C and C-H···N=C H-bonds and van der Waals interactions forming a layered structure, whereas in compound [5a] the molecular conformation is stabilized via intramolecular C-H···O H-bond and molecule interacts with other molecule generated via 21-screw via bifurcated C-H···O=C along with C-H···N=C H-bonds, which are interacting with nitro- of other molecule generated via same symmetry operation, forming bifurcated C-H···O-N H-bonds, which helps in formation of molecular sheet-like structure.Further, in order to understand the various types and nature of intermolecular interactions in the supramolecular structure Hirshfeld surface analysis and fingerprint plot analysis was carried out.

Etherification of HMF to biodiesel additives: The role of NH4+ confinement in Beta zeolites

The role of NH4^+ ion confinement in the catalytic etherification of HMF(5-hydroxymethylfurfural) with ethanol to biodiesel additives was evidenced by studying the catalytic behavior of NH4^+-Beta zeolites with SiO2/Al2O3 ratios of 25 and 75.In order to affect the strength and distribution of the acidic sites, as well as the mobility of NH4^+ ions in the zeolites cages, a secondary level of porosity was introduced in the NH4^+-Beta, presenting a different stability versus alkaline treatment, by using a thermal or an ultrasound assisted method.By analyzing the catalytic behavior in these two series of samples with respect to the changes in porosity by nonlocal density functional theory, structure by XRD, amount of acid sites by FT-IR and mobility of NH4^+ cations by measurements of reversible NH4^+ exchange capacity, was evidenced a decrease in catalytic performances both in terms of rate of HMF depletion and productivity to the main products, when confinement of the ammonium ions is lost due to the introduction of mesoporosity.The high capability of ammonium ions release, associated to the mono-dentate configuration,and the minor confinement effect inside the zeolite pore system, due to the more opened pores structure of mesoporous zeolites, hinders both the direct etherification of HMF to EMF [5-(ethoxymethyl)furan-2-carbaldehyde] and the parallel reaction pathway via acetalization, favoring the rapid desorption of the HMFDEA [5-(hydroxymethyl)furfural diethyl acetal] product out of the crystal and the consequent inhibition of the consecutive reactions to EMFDEA [5-(ethoxymethyl)furfural diethyl acetal] and EMF.

Synthesis and in vitro antimicrobial activity of N-arylquinoline derivatives bearing 2-morpholinoquinoline moiety

A new series of N-arylquinoline derivatives 5a-x bearing 2-morpholinoquinoline moiety has been synthesized by one pot base catalyzed cyclocondensation reaction of 2-morpholinoquinoline-3-carbaldehydes 2a-c,malononitrile 3 andβ-enaminones 4a-h. All the synthesized compounds were screened for their in vitro antimicrobial activity against six bacterial pathogens,namely Streptococcus pneumoniae,Clostridium tetani,Bacillus subtilis,Salmonella typhi,Vibrio cholerae,Escherichia coli and against two fungal pathogens,Aspergillus fumigatus and Candida albicans using broth microdilution MIC method.Of the compounds studied,majority of the compounds were found to active against C.tetani,B.subtilis and C.albicans as compared to first-line standard drugs.

Enantioselective organocatalytic synthesis of the chiral chromenes by domino oxa-Michael-aldol reaction

The proline based chiral organocatalyst has been found to be an efficient catalyst for the facile synthesis of substituted 2-aryl-2 H-chromenes-3-carbaldehyde. We envisioned that the iminium interaction between chiral amino catalysts and a,b-unsaturated carbonyl group was beneficial along with thiourea group as hydrogen bond donor, heterocyclic amines as general base in the domino oxa-Michael-aldol reaction. This catalytic system provided the products in good to high yields（73%–96%） with excellent enantioselectivity（up to 97%） and reasonable reaction time. The atom economy, high yield and mild reaction conditions are some of the important features of this protocol.

Propylphosphonic anhydride(T3P~) catalyzed one-pot synthesis of α-aminonitriles

The Strecker reaction was performed via a one-pot three component condensation of hetero aromatic/ aromatic aldehydes, secondary amines and trimetylsilyl cyanide in the presence of propylphosphonic anhydride （T3P） to accomplish the corresponding α-aminonitriles. The main advantages of this method are very short reaction time and excellent yields.