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Chemical Permeation through Disposable Gloves
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
The need to test the permeation of isocyanates compounds through disposable gloves has arisen from isocyanates being a skin sensitizer and causative agent for allergic contact dermatitis.37–40 Isocyanate compounds are used in several industries beyond the collision repair industry and construction, as well as in many products and applications, e.g., in foams, bed liners, adhesives, insulation, varnishes, and isocyanate paints.41,42Figure 24.3 shows an example of the PPE worn by a worker using an isocyanate. Isocyanates include diisocyanates both in monomer and polymer forms. Monomer diisocyanates include methylenebis (phenyl isocyanate) (MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI), followed by less common naphthalene diisocyanate (NDI), methylene bis-cyclohexylisocyanate (HMDI) (hydrogenated MDI), and isophorone diisocyanate (IPDI). Examples of widely used polyisocyanates include HDI biuret and HDI isocyanurate.
Discovery of new 6-ureido/amidocoumarins as highly potent and selective inhibitors for the tumour-relevant carbonic anhydrases IX and XII
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Ashraf K. El-Damasy, Hyun Ji Kim, Alessio Nocentini, Seon Hee Seo, Wagdy M. Eldehna, Eun-Kyoung Bang, Claudiu T. Supuran, Gyochang Keum
As depicted in Scheme 1, the synthesis of the target ureidocoumarins 5a–p was accomplished in a straightforward manner utilising 6-aminocoumarin 3 as the main building block. Treatment of 2-hydroxy-5-nitrobenzaldehyde 1 with acetic anhydride in a solution of polyphosphoric acid (PPA)/DMF at 145 °C yielded 6-nitrocoumarin 238. Reduction of 2 by either iron powder in AcOH:EtOH:water36, or SnCl2 dihydrate in ethanol39 afforded the corresponding amine 3 in good yield. Treatment of the amine with the appropriate phenyl isocyanate 4a–p in acetonitrile under argon atmosphere gave the 6-ureidocoumarins 5a–p. On the other hand, coupling of amine 3 with the pertinent benzoic acids 6a–c was achieved using O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU) and diisopropylethylamine (DIPEA, Hünig’s base) in DMF under anhydrous conditions to afford the target 6-amidocoumarins 7a–c (Scheme 2).
Synthesis and evaluation of 2,4,5-trisubstitutedthiazoles as carbonic anhydrase-III inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Bilal A. Al-Jaidi, Pran Kishore Deb, Soha Taher Telfah, Abdel Naser Dakkah, Yazan A. Bataineh, Qutaiba Ahmed Al Khames Aga, Mohammad A. Al-dhoun, Ala’ Ali Ahmad Al-Subeihi, Haifa’a Marouf Odetallah, Sanaa K. Bardaweel, Raghuprasad Mailavaram, Katharigatta N. Venugopala, Anroop B. Nair
Compound 13/14/16 (1.5 mM) was dissolved in dry dimethyl formamide, and phenyl isocyanate (2.0 mM) was added to the reaction. The reaction mixture was stirred at room temperature for 24 h. Solvent was evaporated to dryness, and the solid residue thus obtained was recrystallized with ethyl acetate and hexane to get the compounds 13b, 4d, and 16b, respectively, in quantitative yields. Compound 13b on further hydrolysis with sodium hydroxide resulted in the formation of compound 13c.
Towards discovery of novel scaffold with potent antiangiogenic activity; design, synthesis of pyridazine based compounds, impact of hinge interaction, and accessibility of their bioactive conformation on VEGFR-2 activities
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Maiy Y. Jaballah, Rabah A. T. Serya, Nasser Saad, Sohair M. Khojah, Marawan Ahmed, Khaled Barakat, Khaled A. M. Abouzid
In Scheme 4, nucleophilic substitution of 3.6-dichloropyridaizine with 4-nitroaniline yielded 6-chloro-N-(4-nitrophenyl)pyridazin-3-amine; which was further reacted with sodium methoxide the 6-chloropyridazin-3-yl)nitro)phenyl derivatives was refluxed with sodium methoxide to furnish 6-methoxy-N-(4-nitrophenyl)pyridazin-3-amine (14) in high yield. Following catalytic hydrogenation of Compound (14); condensation with substituted phenyl isocyanate furnished compound 15.