Rearrangement phenol thiocarbamates

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. 

FREUDENBERG - SCHdNBERG Xanthate Rearrangement Rearrangement of S-methyl xanthates to S-methyIdithiocarbonatas (conversion of alcohols lo thiols via xanthates, also phenols to thiophenols via thiocarbamates). 

Thioamide formation benzodiazepinone, 505 heteiodiazepinone, 621 phosphorus pentasulf ide, 323, 600 Thioazole formation, nitrile addition, 301 Thiocarbamate formation, 588 phenol, 95 rearrangement, 517 Thioenol ether formation, 185, 517 addition-elimination, 554 Thioester formation, mixed anhydride, 184 Thioether formation, 241, 300, 413, 416 alkylation, 586, 588 aromatic displacement, 416 Thiohydantoin formation, 293 Thiol interchange, benzothiazole formation, 422... 

The position of a trimethylsilyl substituent in phenols 33 determines great yield differences in both thiocarbamate formation and rearrangement [57, 58]. The required TMS-substituted phenols, which were prepared from the respective bromophenols, were tested under standard conditions (Scheme 19). The yield of the rearrangement decreased as the substituent moved from para to ortho. 

Conversion of phenols to thiophenols via rearrangement of thiocarbonates or thiocarbamates (see 1st edition). 

In the Newman-Kwart Rearrangement (NKR), intramolecular aryl migration of O-thioearbamates at high temperatures leads to S-thiocarbamates. The NKR allows access to thiophenols from phenols, as O-thiocarbamates are readily prepared and hydrolysis of S-thiocarbamates can readily be achieved (Moseley and Lenden, 2007). The yield ranges between 72-91%. 

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