Newman rearrangement

Phenols may be converted in thiocarbamates (ArSCONRj) by a Newman rearrangement amino-thiocarbamates, are thus accessible from aminophenols. This provides a convenient route to 2-benzothiazolones. 

Zonta C, De Lucchi O, Volpicelli R, Cotarca L (2007) Thione-Thiol Rearrangement Miyazaki-Newman-Kwart Rearrangement and Others. 275 131-161... 

The Newman-Kuart rearrangement is an example of a high-temperature reaction [34]. With the use of a microreactor, the reaction temperature could be extended up to 200 °C. 0-(2-Nitrophenyl)-N,N-dimethylthiocarbamate was converted to S-(2-nitro-phenyl)-N,N-dimethylcarbamothioate at 170 °C in 14 min at 90% yield. Quantitative conversion with a throughput of 34 g/h was achieved with sulfolane as solvent at the same temperature and reaction time. 

Scheme 33. DoM of aryl O-thiocarbamate. Link to the Newman-Kwart rearrangement and consequent S-thiocarbamate cross-coupling.

A Newman-Kwart rearrangement features in a synthesis of 3,8-diiododibenzo-l,2-dithiin which possesses a screw-boat conformation. The substituents allow elaboration of the molecule, though preferably prior to formation of the thiin ring <06TL9135>. 

A Newman-Kwart rearrangement of the O-thiocarbamoy I derivative of a thiacalix[4]arene results in the synthesis of thiacalix[2]thianthrenes 69. The two thianthrene units are linked by two sulfur bridges producing a basket-shaped molecule <07TL5401>. Treatment with... 

Dinaphthothiophene 530 is synthesized by the Newman-Kwait rearrangement of dithiocarbamoyl derivative 529 <200581109>. 

The method described here represents a modified Arndt-Eistert reaction as developed by Newman and Beal.7 This modification gives results that are more reproducible than those of the original Arndt-Eistert reaction and, in general, allows the rearrangement to be carried out successfully on larger-scale runs. The use of triethylamine in the formation of diazo ketones makes possible the use of only one equivalent of diazomethane.8... 

Abstract Thione-to-thiol rearrangements represent a general route for the synthesis of sulfur compounds from hydroxyl functionalities. In particular, the Miyazaki-Newman-Kwart rearrangement has been widely used for the synthesis of aromatic thiols from the corresponding phenols. 

Keywords Thermal rearrangement Newman-Kwart rearrangement Aromatic thiols... 

However, during the bibliographical search we became aware of a previous report, followed by other important contributions on the subject, by Miyazaki [3]. For this reason we propose the name Miyazaki-Newman-Kwart (MNK) for the rearrangement. 

Since the original paper by Newman, it has been well known that the presence of an acetyl group in the 2 position gives very poor yields of rearranged products [70]. The problem was solved by performing the reaction in re-... 

Another description of large scale analysis come from AstraZeneca in a study directed towards the synthesis of a neurokinin inhibitor of the central nervous system [100]. The synthesis inherited from the research stage already contained a Newman-Kwart rearrangement for the introduction of the sulfur atom (Scheme 40). This step was maintained in the reaction scale-up [101,102]. 

The synthesis of these thiols is relatively straightforward from commercially available phenols via the Newman-Karnes rearrangement (6) (Eq. (1)) or from sulfonyl chlorides (also obtainable commercially) by Li[AlH4] reduction (7) (Eq. (2)). 

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