Iodine-Mediated Cross-Dehydrogenative Coupling of Heterocyclic Thiols with Amines: An Easy and Practical Formation of S?N Bond
An efficient iodine-mediated construction of S?N bond was developed. Such a cross-dehydrogenative coupling of heterocyclic thiols with amines proceeded smoothly under metal-free and base-free conditions, and afforded a series of sulfenamides in good to excellent yields. The easily available substrates and convenient synthetic procedure illustrate potential synthetic value of this protocol for the preparation of sulfenamide related biologically or pharmaceutically active compounds.
Scalable electrochemical oxidant-and metal-free dehydrogenative coupling of S-H/N-H
A practical and scalable electrochemical oxidation of S-H and N-H was developed. This oxidant- and catalyst-free electrochemical process enables S-N bond formation with inexpensive nickel electrodes in an undivided cell. This procedure exhibits broad substrate scopes and good functional-group compatibility. A 50 g scale oxidative coupling augurs well for industrial applications.
Reusable cobalt-phthalocyanine in water: Efficient catalytic aerobic oxidative coupling of thiols to construct S-N/S-S bonds
A new aerobic oxidative coupling of thiols in water to construct sulfenamides or disulfides was developed, utilizing cobalt(ii)phthalocyanine-tetra-sodium sulfonate as the catalyst and O2 as the oxidant. The mother liquor could be recycled up to 20 times with negligible loss of activity and only a minor decrease of product yield.
Process for the preparation of benzothiazole-2-sulphenamides
In a process for the production of benzothiazole-2-sulphenamides, a 2-mercaptobenzothiazole in the form of a particulate solid or a dispersion of a particulate solid in a liquid carrier is added gradually and concurrently with an aqueous solution of sodium hypochlorite to a solution of an amine in a mixture of water and a water-miscible organic solvent, the amount of amine being not more than 1.25 moles per mole of 2-mercaptobenzothiazole. A feature of the process is that it represents a significant improvement over prior art methods for the production of sulphenamides derived from secondary amines such as dicyclohexylamine and diisopropylamine.
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(2008/06/13)
Process for the preparation of N,N-diisopropylbenzothiazyl-2-sulfenamide
There is disclosed a process for the preparation of N,N-diisopropylbenzothiazyl-2-sulfenamide which comprises contacting an aqueous mixture of diisopropylamine and 2-mercaptobenzothiazole with an oxidizing agent in the presence of sufficient acid to neutralize the excess base, if any, in the oxidizing agent wherein the molar ratio of diisopropylamine to 2-mercaptobenzothiazole is at least 1.5 to 1.
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(2008/06/13)
ON THE REACTION OF BENZOTHIAZOL-2-YL SULPHENAMIDES WITH PHOSPHITES
A study of the synthesis of phosphoramidates from phosphites and benzothiazol-2-yl-sulphenamides, indicates that a quinquecovalent phosphorane is an intermediate.Since the initial step in this reaction does not involve attack of phosphorus on nitrogen, it is unlikely that these sulphenamides will act as electrophilic aminating agents towards non-phosphorus nucleophiles.An efficient new method for preparing benzothiazol-2-yl-sulphenamides is reported.
Brownbridge, P.,Jowett, I. C.
p. 311 - 318
(2007/10/02)
Manufacture of sulfenamides
Processes for the manufacture of sulfenamides by the oxidation of a mixture of 2-mercaptobenzothiazole and the appropriate amine in a critical amount of water and/or organic solvent produces a pure product of good quality and high yield. The amount of water should be in the range of from 10 to 30% by weight based on the total reaction mixture.
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(2008/06/13)
Process for the preparation of thiazolesulphenamides
Thiazolesulphenamides, useful as rubber vulcanization accelerators, are made by reaction of a 2-mercapto-thiazole or a 2,2'-dithiazolyl disulphide with ammonia or a primary or secondary amine in the presence of oxygen and a copper catalyst of specified kind.