The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Henry C. Kelly - One of the best experts on this subject based on the ideXlab platform.
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synthesis and comparative reactivity of Thiomorpholine borane aqueous hydrolysis and oxidation by hypochlorite
Inorganica Chimica Acta, 1999Co-Authors: Carlos A. Amezcua, Kevin E. Bell, Henry C. KellyAbstract:Abstract Thiomorpholine-N-borane was synthesized via amine displacement of BH3 from tetrahydrofuran–borane which had been prepared from NaBH4 and BF3·Et2O in tetrahydrofuran. Acid-catalyzed hydrolysis occurs only slightly faster than for morpholine–borane, the difference being attributed to a small difference in the electronic inductive effects of sulfur and oxygen in the 4-position of the respective adducts. Reaction with NaOCl exhibits a stoichiometric [OCl−]:[S(CH2)4NHBH3] ratio of 5:1. This is attributed to consumption of 3 mol of hypochlorite for the oxidation of hydridic hydrogen in BH3, one for the chlorination of nitrogen and another in attack at sulfur presumably resulting in sulfoxide formation. At pH 9.1–10.4, the initial reaction of hypochlorite with Thiomorpholine–borane is several times faster than with morpholine–borane and, unlike the reaction with morpholine–borane, relatively insensitive to pH. Whereas hypochlorite oxidation of morpholine–borane has been proposed to occur primarily through reaction with HOCl, it is speculated that Thiomorpholine–borane is also susceptible to attack by hypochlorite ion.
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Synthesis and comparative reactivity of Thiomorpholine–borane: aqueous hydrolysis and oxidation by hypochlorite
Inorganica Chimica Acta, 1999Co-Authors: Carlos A. Amezcua, Kevin E. Bell, Henry C. KellyAbstract:Abstract Thiomorpholine-N-borane was synthesized via amine displacement of BH3 from tetrahydrofuran–borane which had been prepared from NaBH4 and BF3·Et2O in tetrahydrofuran. Acid-catalyzed hydrolysis occurs only slightly faster than for morpholine–borane, the difference being attributed to a small difference in the electronic inductive effects of sulfur and oxygen in the 4-position of the respective adducts. Reaction with NaOCl exhibits a stoichiometric [OCl−]:[S(CH2)4NHBH3] ratio of 5:1. This is attributed to consumption of 3 mol of hypochlorite for the oxidation of hydridic hydrogen in BH3, one for the chlorination of nitrogen and another in attack at sulfur presumably resulting in sulfoxide formation. At pH 9.1–10.4, the initial reaction of hypochlorite with Thiomorpholine–borane is several times faster than with morpholine–borane and, unlike the reaction with morpholine–borane, relatively insensitive to pH. Whereas hypochlorite oxidation of morpholine–borane has been proposed to occur primarily through reaction with HOCl, it is speculated that Thiomorpholine–borane is also susceptible to attack by hypochlorite ion.
Carlos A. Amezcua - One of the best experts on this subject based on the ideXlab platform.
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synthesis and comparative reactivity of Thiomorpholine borane aqueous hydrolysis and oxidation by hypochlorite
Inorganica Chimica Acta, 1999Co-Authors: Carlos A. Amezcua, Kevin E. Bell, Henry C. KellyAbstract:Abstract Thiomorpholine-N-borane was synthesized via amine displacement of BH3 from tetrahydrofuran–borane which had been prepared from NaBH4 and BF3·Et2O in tetrahydrofuran. Acid-catalyzed hydrolysis occurs only slightly faster than for morpholine–borane, the difference being attributed to a small difference in the electronic inductive effects of sulfur and oxygen in the 4-position of the respective adducts. Reaction with NaOCl exhibits a stoichiometric [OCl−]:[S(CH2)4NHBH3] ratio of 5:1. This is attributed to consumption of 3 mol of hypochlorite for the oxidation of hydridic hydrogen in BH3, one for the chlorination of nitrogen and another in attack at sulfur presumably resulting in sulfoxide formation. At pH 9.1–10.4, the initial reaction of hypochlorite with Thiomorpholine–borane is several times faster than with morpholine–borane and, unlike the reaction with morpholine–borane, relatively insensitive to pH. Whereas hypochlorite oxidation of morpholine–borane has been proposed to occur primarily through reaction with HOCl, it is speculated that Thiomorpholine–borane is also susceptible to attack by hypochlorite ion.
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Synthesis and comparative reactivity of Thiomorpholine–borane: aqueous hydrolysis and oxidation by hypochlorite
Inorganica Chimica Acta, 1999Co-Authors: Carlos A. Amezcua, Kevin E. Bell, Henry C. KellyAbstract:Abstract Thiomorpholine-N-borane was synthesized via amine displacement of BH3 from tetrahydrofuran–borane which had been prepared from NaBH4 and BF3·Et2O in tetrahydrofuran. Acid-catalyzed hydrolysis occurs only slightly faster than for morpholine–borane, the difference being attributed to a small difference in the electronic inductive effects of sulfur and oxygen in the 4-position of the respective adducts. Reaction with NaOCl exhibits a stoichiometric [OCl−]:[S(CH2)4NHBH3] ratio of 5:1. This is attributed to consumption of 3 mol of hypochlorite for the oxidation of hydridic hydrogen in BH3, one for the chlorination of nitrogen and another in attack at sulfur presumably resulting in sulfoxide formation. At pH 9.1–10.4, the initial reaction of hypochlorite with Thiomorpholine–borane is several times faster than with morpholine–borane and, unlike the reaction with morpholine–borane, relatively insensitive to pH. Whereas hypochlorite oxidation of morpholine–borane has been proposed to occur primarily through reaction with HOCl, it is speculated that Thiomorpholine–borane is also susceptible to attack by hypochlorite ion.
Kevin E. Bell - One of the best experts on this subject based on the ideXlab platform.
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synthesis and comparative reactivity of Thiomorpholine borane aqueous hydrolysis and oxidation by hypochlorite
Inorganica Chimica Acta, 1999Co-Authors: Carlos A. Amezcua, Kevin E. Bell, Henry C. KellyAbstract:Abstract Thiomorpholine-N-borane was synthesized via amine displacement of BH3 from tetrahydrofuran–borane which had been prepared from NaBH4 and BF3·Et2O in tetrahydrofuran. Acid-catalyzed hydrolysis occurs only slightly faster than for morpholine–borane, the difference being attributed to a small difference in the electronic inductive effects of sulfur and oxygen in the 4-position of the respective adducts. Reaction with NaOCl exhibits a stoichiometric [OCl−]:[S(CH2)4NHBH3] ratio of 5:1. This is attributed to consumption of 3 mol of hypochlorite for the oxidation of hydridic hydrogen in BH3, one for the chlorination of nitrogen and another in attack at sulfur presumably resulting in sulfoxide formation. At pH 9.1–10.4, the initial reaction of hypochlorite with Thiomorpholine–borane is several times faster than with morpholine–borane and, unlike the reaction with morpholine–borane, relatively insensitive to pH. Whereas hypochlorite oxidation of morpholine–borane has been proposed to occur primarily through reaction with HOCl, it is speculated that Thiomorpholine–borane is also susceptible to attack by hypochlorite ion.
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Synthesis and comparative reactivity of Thiomorpholine–borane: aqueous hydrolysis and oxidation by hypochlorite
Inorganica Chimica Acta, 1999Co-Authors: Carlos A. Amezcua, Kevin E. Bell, Henry C. KellyAbstract:Abstract Thiomorpholine-N-borane was synthesized via amine displacement of BH3 from tetrahydrofuran–borane which had been prepared from NaBH4 and BF3·Et2O in tetrahydrofuran. Acid-catalyzed hydrolysis occurs only slightly faster than for morpholine–borane, the difference being attributed to a small difference in the electronic inductive effects of sulfur and oxygen in the 4-position of the respective adducts. Reaction with NaOCl exhibits a stoichiometric [OCl−]:[S(CH2)4NHBH3] ratio of 5:1. This is attributed to consumption of 3 mol of hypochlorite for the oxidation of hydridic hydrogen in BH3, one for the chlorination of nitrogen and another in attack at sulfur presumably resulting in sulfoxide formation. At pH 9.1–10.4, the initial reaction of hypochlorite with Thiomorpholine–borane is several times faster than with morpholine–borane and, unlike the reaction with morpholine–borane, relatively insensitive to pH. Whereas hypochlorite oxidation of morpholine–borane has been proposed to occur primarily through reaction with HOCl, it is speculated that Thiomorpholine–borane is also susceptible to attack by hypochlorite ion.
Srinivas Kantevari - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of novel morpholine, Thiomorpholine and N-substituted piperazine coupled 2-(thiophen-2-yl)dihydroquinolines as potent inhibitors of Mycobacterium tuberculosis.
European journal of medicinal chemistry, 2018Co-Authors: Sandeep Kumar Marvadi, Vagolu Siva Krishna, Dharmarajan Sriram, Srinivas KantevariAbstract:Abstract A series of novel morpholine, Thiomorpholine and N-substituted piperazine coupled 2-(thiophen-2-yl)dihydroquinolines 7a–p was designed and synthesized from 2-acetyl thiophene in six step reaction sequence involving modified Bohlmann-Rahtz and Vilsmeier-Haack-Arnold reactions as key transformations. 2-(Thiophen-2-yl)dihydroquinoline was formylated and subsequently chlorinated using DMF-POCl3. The resulting aldehyde was reduced to give an alcohol and then converted to bromide using PBr3. Further coupling of bromide with morpholine, Thiomorpholine and N-substituted piperazines resulted in the desired quinolines 7a-p in very good yields. All the new derivatives 7a–p were characterized by their NMR and mass spectral analysis. In vitro screening of new compounds for antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB), resulted in two derivatives 7f and 7p as most potent antitubercular agents (MIC:1.56 μg/mL) with lower cytotoxicity profiles.
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Click-based synthesis and antitubercular evaluation of novel dibenzo[b,d]thiophene-1,2,3-triazoles with piperidine, piperazine, morpholine and Thiomorpholine appendages
Bioorganic & medicinal chemistry letters, 2016Co-Authors: Lokesh Pulipati, Dharmarajan Sriram, Perumal Yogeeswari, Srinivas KantevariAbstract:A series of novel piperidine, piperazine, morpholine and Thiomorpholine appended dibenzo[b,d]thiophene-1,2,3-triazoles were designed and synthesized utilizing azide-alkyne click chemistry in the penultimate step. The required azide building block 6a-e was synthesized from commercial dibenzo[b,d]thiophene in good yields following five step reaction sequence. All the new analogues 8a-f, 9a-f, 10a-f, 11a-f &12a-f were characterized by their NMR and mass spectral analysis. Screening all thirty new compounds for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv, resulted 8a, 8f and 11e as potent analogues with MIC 0.78μg/mL, 0.78μg/mL & 1.56μg/mL, respectively, and has shown lower cytotoxicity. Interestingly, all six piperazine appended dibenzo[b,d]thiophene-1,2,3-triazoles 11a-f exhibited Mtb inhibition activity with MIC 1.56-12.5μg/mL. To some extent, the data observed here indicated Mycobacterium tuberculosis inhibition among the appendages is in the order, piperazine>Thiomorpholine>morpholine.
Simon Leung - One of the best experts on this subject based on the ideXlab platform.
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Development of a Safe and High-Throughput Continuous Manufacturing Approach to 4-(2-Hydroxyethyl)Thiomorpholine 1,1-Dioxide
Organic Process Research & Development, 2018Co-Authors: Neil A. Strotman, Yichen Tan, Kyle W. Powers, Maxime Soumeillant, Simon LeungAbstract:Continuous processing enabled the highly energetic double conjugate addition of ethanolamine to divinylsulfone to prepare 2 kg of 4-(2-hydroxyethyl)Thiomorpholine 1,1-dioxide, as an intermediate in the synthesis of HIV Maturation Inhibitor BMS-955176. In situ IR was employed to monitor the steady state of the transformation for increased robustness via appearance of the Thiomorpholine dioxide moiety and disappearance of the divinylsulfone. Surprisingly, a series of oligomers formed as intermediates, which converted to product with extended aging or heating, consistent with computational predictions. By running this process in flow, the highly exothermic reaction could be safely executed in an equal volume of water as the only solvent, despite an adiabatic temperature rise of 142 °C, leading to a streamlined and efficient process.
