1,9-Dithia[2.2]paracyclophane:  Synthesis, Molecular Structure, and Properties

Itoh, Takahito; Gotoh, Kenji; Ishikawa, N.; Hamaguchi, Tatsuya; Kubo, Masataka

doi:10.1021/jo951426c

Cited by 7 publications

(3 citation statements)

References 18 publications

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“…The geometry around the sulfur is 'V' shaped with a C(14)eS(1)eC(5) angle of 104.03 (19) and the geometry around C(9) and C(12) is distorted tetrahedral due steric overcrowding. The C(Sp 2 )eS bond length [1.777 (4) Å] is slightly shorter than that found in 5,5 0 -dibromo-2,2 0 -dipryidyl disulfide (1.782 Å) [15] and the C(Sp 3 )eS bond length [1.787 (4) Å] is significantly shorter than that found in other organosulfur compounds having C(Sp 3 )eS bond [16,17].…”

Section: Thermogravimetric Studiesmentioning

confidence: 89%

Synthesis and characterization of chalcogen (S and Se) derivatives of 4-chloro- and 4-methoxy-N,N-diisopropylpyridine-2-carboxamide: X-ray structure of 4-methoxy-3-(sulfanylmethyl)- and 4-chloro-3-(selenenylbenzyl)-N,N-diisopropylpyridine-2-carboxamide

Dhau

Dhir

Singh

2011

Journal of Organometallic Chemistry

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Section: Thermogravimetric Studiesmentioning

confidence: 89%

Synthesis and characterization of chalcogen (S and Se) derivatives of 4-chloro- and 4-methoxy-N,N-diisopropylpyridine-2-carboxamide: X-ray structure of 4-methoxy-3-(sulfanylmethyl)- and 4-chloro-3-(selenenylbenzyl)-N,N-diisopropylpyridine-2-carboxamide

Dhau

Dhir

Singh

2011

Journal of Organometallic Chemistry

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“…Lysozyme was obtained from Roche Molecular Biochemicals, Indianapolis, IN. Amino-2-propanethiol hydrochloride and 4-mercaptobenzyl alcohol were prepared as described elsewhere. All the synthetic procedures below, although written for derivatives of mPEG5K, are equally applicable to the mPEG12K analogues (gifts from Union Carbide and NOF, respectively).…”

Section: Methodsmentioning

confidence: 99%

Thiolytically Cleavable Dithiobenzyl Urethane-Linked Polymer–Protein Conjugates as Macromolecular Prodrugs: Reversible PEGylation of Proteins

Zalipsky¹,

Mullah²,

Engbers³

et al. 2007

Bioconjugate Chem.

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New thiolytically cleavable dithiobenzyl (DTB) urethane-linked conjugates of methoxypoly(ethylene glycol) (mPEG) and a model protein, lysozyme, were prepared and thoroughly characterized. In contrast to our earlier communication [Zalipsky, et al. (1999) Bioconjugate Chem. 10, 703], in the current study we used a more sterically hindered form of para-DTB urethane linkage containing a methyl group on the alpha-carbon to the disulfide moiety. The new reagent for covalent attachment of mPEG-DTB to amino groups of proteins was synthesized via a seven-step process. As a result of PEG conjugation, the lysozyme was shown to completely lose its bacterial cell wall-lysing activity. However, activity was almost fully restored upon cysteine-mediated cleavage of the PEG component. The conjugate decomposition process was monitored by RP-HPLC and by ion spray LC-MS, which showed the formation of the p-mercaptobenzyl urethane-lysozyme intermediate, and ultimately its conversion to the unmodified lysozyme as the sole protein component. Pharmacokinetic evaluation of (125)I-labeled cleavable and noncleavable PEG-lysozyme given intravenously in rats revealed similar clearance patterns; both cleared in a significantly slower manner compared to that of the native protein. However, subcutaneous administration of the same conjugates showed a significantly larger AUC of the cleavable conjugate, indicating that some cleavage of the DTB urethane may have occurred. Although the DTB-linked PEG-lysozyme exhibited almost the same plasma clearance as the noncleavable counterpart, hinting that methyl-DTB linkage might be stable in the bloodstream, SDS-PAGE examination of the conjugate incubated in plasma showed decomposition at least partially mediated by albumin. These results suggest the potential of PEG-DTB-proteins as macromolecular prodrugs capable of generating fully active native proteins under in vivo conditions.

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“…It should be pointed out that photochemical studies of thioketones are particularly difficult owing to their high photoreactivity towards solvent impurities and oxygen, the need to use very low thione concentrations to prevent BPT triplet deactivation from being dominated by the self-quenching process, possible thermal instability of photoproducts and the tendency of the photoproducts to undergo further photoreactions leading to the formation of polymers. [3][4][5][10][11][12] …”

Section: Introductionmentioning

confidence: 99%

Photochemical reactions ofT1 benzopyranthione 3-methylpentane

Kozłowski

Maciejewski

Milewski

et al. 1999

J. Phys. Org. Chem.

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Photochemical properties of the lowest triplet state of 4H-1-benzopyran-4-thione (BPT) in 3-methylpentane were studied in the thione concentration range 10 À7 À 10 À3 M. The quantum yield of the photochemical decomposition of BPT was found to be highly concentration dependent. For low BPT concentrations (`10 À6 M) a reaction with the solvent is responsible for the consumption of the thione. In the concentration range 1 Â 10 À6 -8 Â 10 À5 M the main process is the reaction of thiyl radicals, formed in the primary reaction of hydrogen abstraction from a solvent molecule, with BPT molecules in the ground state. For thione concentrations b10 À4 M, the BPT triplet decays almost entirely in a self-quenching process. HPLC analysis showed that five different photoproducts, including an oligomer, are formed. Knowledge of earlier studied photophysical properties of BPT in 3-methylpentane and perfluoroalkanes permitted a quantitative explanation of the mechanism of photochemical reactions of 3 (BPT). The studies indicate, for BPT concentrations`10 À4 M, a dominant role of the interaction of 3 (BPT) with the solvent and the subsequent caged radical recombination in deactivation of BPT in the T 1 state.

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1,9-Dithia[2.2]paracyclophane: Synthesis, Molecular Structure, and Properties

Cited by 7 publications

References 18 publications

Synthesis and characterization of chalcogen (S and Se) derivatives of 4-chloro- and 4-methoxy-N,N-diisopropylpyridine-2-carboxamide: X-ray structure of 4-methoxy-3-(sulfanylmethyl)- and 4-chloro-3-(selenenylbenzyl)-N,N-diisopropylpyridine-2-carboxamide

Synthesis and characterization of chalcogen (S and Se) derivatives of 4-chloro- and 4-methoxy-N,N-diisopropylpyridine-2-carboxamide: X-ray structure of 4-methoxy-3-(sulfanylmethyl)- and 4-chloro-3-(selenenylbenzyl)-N,N-diisopropylpyridine-2-carboxamide

Thiolytically Cleavable Dithiobenzyl Urethane-Linked Polymer–Protein Conjugates as Macromolecular Prodrugs: Reversible PEGylation of Proteins

Photochemical reactions ofT1 benzopyranthione 3-methylpentane

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