- P(III)-Mediated Cascade C-N/C-S Bond Formation: A Protocol towards the Synthesis of N,S-Heterocycles and Spiro Compounds
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A P(III)-mediated entry towards construction of C?N/C?S bond has been devised. The developed heterocyclization method was exercised for the synthesis of a diverse range of N,S-heterocycles and related spiro molecules. P(NMe2)3 revealed the maximum efficacies under the aerobic reaction conditions and a spectrum of bis-nucleophiles, and isothiocyanates were tolerated well to serve the access of manifold immense molecules. (Figure presented.).
- Polina, Saibabu,Putta, V. P. Rama Kishore,Gujjarappa, Raghuram,Singh, Virender,Pujar, Prasad Pralhad,Malakar, Chandi C.
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supporting information
p. 431 - 445
(2020/12/07)
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- Dual targeting of adenosine A2A receptors and monoamine oxidase B by 4H-3,1-benzothiazin-4-ones
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Blockade of A2A adenosine receptors (A2AARs) and inhibition of monoamine oxidase B (MAO-B) in the brain are considered attractive strategies for the treatment of neurodegenerative diseases such as Parkinson's disease (PD). In the present study, benzothiazinones, e.g., 2-(3-chlorophenoxy)- N-(4-oxo-4H-3,1-benzothiazin-2-yl)acetamide (13), were identified as a novel class of potent MAO-B inhibitors (IC50 human MAO-B: 1.63 nM). Benzothiazinones with large substituents in the 2-position, e.g., methoxycinnamoylamino, phenylbutyrylamino, or chlorobenzylpiperazinylbenzamido residues (14, 17, 27, and 28), showed high affinity and selectivity for A 2AARs (Ki human A2AAR: 39.5-69.5 nM). By optimizing benzothiazinones for both targets, the first potent, dual-acting A2AAR/MAO-B inhibitors with a nonxanthine structure were developed. The best derivative was N-(4-oxo-4H-3,1-benzothiazin-2-yl)-4-phenylbutanamide (17, Ki human A2A, 39.5 nM; IC50 human MAO-B, 34.9 nM; selective versus other AR subtypes and MAO-A), which inhibited A 2AAR-induced cAMP accumulation and showed competitive, reversible MAO-B inhibition. The new compounds may be useful tools for validating the A2AAR/MAO-B dual target approach in PD.
- St??el, Anne,Schlenk, Miriam,Hinz, Sonja,Küppers, Petra,Heer, Jag,Gütschow, Michael,Müller, Christa E.
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p. 4580 - 4596
(2013/07/19)
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- Synthesis and biological activity of N-aroyl-N′-substituted thiourea derivatives
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A series of N-aroyl-N′-substituted thiourea derivatives have been prepared in good to excellent yields under the condition of solid-liquid phase transfer catalysis using polyethylene glycol-400(PEG-400) as the catalyst. The products have been characterize
- Zhang,Wei,Gao
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p. 3099 - 3105
(2007/10/03)
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- 3,1-Benzothiazin-4-ones and 3,1-benzoxazin-4-ones: Highly different activities in chymotrypsin inactivation
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3,1-Benzothiazin-4-ones are sulfur analogs of the potent serine protease inactivators of the 3,1-benzoxazin-4-one type, which acylate the serine residue within the active site of the enzymes. A series of 2-amino-3,1-benzothiazinones was synthesized, but these compounds showed only very little inhibitory activity toward chymotrypsin, a model serine protease. Detailed investigations revealed that benzothiazinones and benzoxazinones react with identical mechanisms, but benzothiazinones acylate chymotrypsin with much lower rate constants. Investigations of nonenzymatic hydrolysis showed the benzothiazinones to be intrinsically more stable than benzoxazinones. It was concluded from spectroscopic results, that benzoxazinones are highly activated due to the absence of ester-like resonance. 2-Benzoylamino-4H-3,1-benzoxazin-4-one was found to be a new, highly active chymotrypsin inactivator. In contrast, benzothiazinones were found to be resonance stabilized. The contribution of a resonance structure with an exocyclic oxanion to the overall structure of the benzothiazinones and its nonproductive binding to the active site explained their low reactivity toward chymotrypsin.
- Neumann,Guetschow
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- REACTIONS OF N-BENZOYL ISOTHIOCYANATE WITH ANTHRANILIC ACID AND METHYL ANTHRANILATE
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N-Benzoyl-N'-(2-carboxy- and -2-methoxycarbonylphenyl)thioureas have been obtained by the reaction of N-benzoyl isothiocyanate with anthranilic acid and methyl anthranilate, respectively.Kinetics of cyclization of these compounds into 2-mercapto-3,4-dihydro-4-quinazolone have been studied in water and in methanol.In the base-catalyzed cyclization of N-benzoyl-N'-(2-carboxyphenyl)thiourea the proper cyclization is preceded by solvolysis of the benzoyl group.In the case of N-benzoyl-N'-(2-methoxycarbonylphenyl)thiourea the reaction rate is limited by the base-catalyzed cyclization of the starting benzoyl derivative; the benzoyl group is split off in a subsequent rapid step.
- Kavalek, Jaromir,Kotyk, Milan,El Bahaie, Said,Sterba, Vojeslav
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p. 246 - 255
(2007/10/02)
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