In order to synthesize meso- and (2R,4R)-2,4-diaminoglutaric acids, a synthetic route has been developed starting from Garner's aldehyde and where the key steps are the asymmetric hydrogenations of (E)- and (Z)-(R)-3-tert-butoxycarbonyl-2,2-dimethyl-4-[2′-(benzamido)-2′-(methoxycarbonyl)e...

SummaryThe reaction of the 1,3-di-Grignard reagent 1,3-bis(bromomagnesio)-2,2-dimethylpropane (2) with silicon or germanium tetrachloride gave the 2,2,6,6-tetramethyl-4-metallaspiro[3.3]heptanes (1) in 15% (Si) and 48% (Ge) isolated yield, respectively. The spectroscopic properties of1 are brief...

Analysis of the full splitting pattern of the 100 MHz 1H-NMR spectra of diethyl - 2,6 -dibromospiro[3.3]heptane - 2,6 - dicarboxylate (3) in chloroform and benzene and the 220 MHz 1H-NMR spectrum of dimethylspiro[3.3]heptane - 2,6 - dicarboxylate (2) in naphthalene has been carried out. Puckerin...

New non-flattened amino group-containing building blocks and fluorinated analogs based on the spiro[3.3]heptane motif were synthesized. The syntheses included a challenging deoxofluorination of sterically hindered carbonyl groups via an intermediate carbocation. The synthesized compounds could b...

Konjac glucomannan (KGM) was modified with amino acids to synthesize polysaccharide esters (KGMA and KGMH) which were evaluated as corrosion inhibitor for mild steel in 0.5 M HCl solution by weight loss tests, Tafel curves, electrochemical impedance spectroscopy (EIS) and scanning electron micro...

Green/sustainable plant origin organic molecules with structures including polar functional groups, heteroatoms and aromatic rings play a vital role in the adsorption and inhibition effectiveness on metal substance in harsh acidic environments. The components like apigenin, eriodictyol, naringen...

Acidic HCl/glyphosate liquor is produced largely during the production of glyphosate herbicide, which contains 2.5–3.0 mol L−1 HCl, 1.1–1.5 mol L−1 glyphosate and 34–35 wt% other organic components. The acidic liquor is traditionally neutralized to pH 1.5 by alkali (NaOH) for the maximum crys...

Due to the complex mineral composition and structure of sandstone rock as well as the diversity and randomness of acid-rock heterogeneous reactions, the acid-rock reaction mechanisms of sandstone acidizing are not well understood. A model that can be used to describe the kinetic reactions that o...

Novel modified polyaspartic acid with Schiff base structure was synthesized for the first time. Then the corrosion inhibition behavior of polyaspartic acid (PASP) and modified polyaspartic acid (PASP/SB) on carbon steel in 1 M HCl was investigated using gravimetric methods, electrochemical measu...

The corrosion inhibition behaviour of tannic acid (TA), gallic acid (GA) and their blends on mild steel in 1 M HCl solution was studied via electrochemical methods, namely, polarization (Tafel plots) and electrochemical impedance spectroscopy (EIS). The surface morphology of mild steel in 1 M HC...

The inhibition effect of acetohydroxamic acid (AHA) and benzohydroxamic acid (BHA) on corrosive dissolution of copper in 1 M HCl medium was studied using gravimetric, electrochemical (PDP and EIS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy disper...

Acidic HCl/glyphosate liquor is the intermediate product during the production of glyphosate herbicide. The liquor contains about 2.4 mol/L (M) HCl, 1.1 M glyphosate and 35 wt% other organic components, which can be separated by continuous diffusion dialysis (DD) to recover HCl. The residual sol...

A low content of Si is an important characteristic of most Ti metal alloys, and low Si content in Ti sponge from the Kroll process is consistently achievable by the chlorination and distillation step. However, alternative routes are being explored to reduce Ti-metal production costs. One promisi...

The synthesis of the dihydrochloride salts of (R)-1 and (S)-1 2-(aminomethyl)piperidine is reported starting from either (S) or (R) lysine, respectively. A key step in the synthetic protocol involves the in situ formation of aziridinium 8, which then undergoes an intramolecular ring opening with...

The coordination behaviour of tris(aminomethyl)phosphine oxide (tampo) to selected transition metal ions was studied. In the case of Co(III), Ni(II) and Cu(II) complexes with metal-to-ligand 1:2 stoichiometry, bis(tripodal) tampo coordinations forming octahedral coordination spheres (in the case...

The vanillic acid was converted to catechol using a catalyst system of PdAc2/[Na]+[7,8-bis(aminomethyl)-nido-C2B9H10]. The 90.3% yield of catechol was achieved from vanillic acid in 4 h using the system at 240 °C. The reaction was also compared using catalyst system of PdAc2/TMEDA (N,N,N′,N′-...

Butalactin, (2R*,3S*)-2-(4′,5′-epoxy-hex-2′E-en)oyl-2-hydroxy-3-hydroxymethylbutanolide,(1) is a new antibiotic produced by a Streptomyces sp. HIL Y-86,36923. Butalactin is structurally related to the butyrolactones produced as signal molecules by microorganisms.

New subphthalocyanines were synthesized by threatening 2-[4-({(1E)-[4-(dimethylamino)phenyl]methylene}amino)phenyl]ethanol 2 and 2-[4-({(1E)-[4-(diethylamino)phenyl]methylene}amino)phenyl]ethanol 3 with excess of boron subphthalocyanine chloride in toluene. The subphthalocyanines containing 2-[4...

A novel class of indole derivatives characterized by a (αE)-α-(1H-indol-3-ylmethylene)benzeneacetic acid or amide scaffold was synthesized. These derivatives, assayed for cell-growth inhibition activity against a panel of six different tumor cell lines, showed strong antiproliferative activity...

A series of 2-(indolylmethylidene)-2,3-dihydro-1-benzofuran-3-ones (aurone-indole hybrids) and 2-(indolyl)-4H-chromen-4-ones (flavone-indole hybrids) were designed, synthesized, and their monoamine oxidase (MAO) A and B inhibitory activities were evaluated. Compounds 5b and 11b showed potent inh...