Rearrangement Tiemann

Treatment of amidoximes, derived from amides and hydroxylamine, with ben-zenesulfonyl chloride and water leads to ureas. 

The substituent anti to the leaving group COS02Ph) migrates. 

Carbocation rearrangement of P-aminoalcohols via diazotization to afford carbonyl compounds. 

Haffer, G. Eder, U. Neef, G. Sauer, G. Wiechert, R. Justus Liebigs Ann. Chem. 1981, 425. 

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The rearrangement of amidoximes to derivatives of urea is called the Tiemann Rearrangement. 

The Tiemann rearrangement of amidoximes affords carbodiimides through a nidene intermediate. For example, reaction of the shown amidoxime 98 with benzenesulfonyl chloride in pyridine affords N-phenyl-N -cyclohexylcarbodiimide 99 in 64 % yield. ... 

DiaryIcarbodiimides are similarly obtained from amidoximes andPOCls in pyridine.The yields range from 51-74 %. Cyclic carbodiimides are also synthesized using the Tiemann rearrangement (see Section 11.2.3). 

The modified Tiemann rearrangement of cyclic amidoxime derivatives 21 (where R = Me, Tos) using aqueous potassium hydroxide is also used to synthesize the listed homocyclic carbodiimides 22. 

TEUBER Oumona synthesis 382 THILE-WINTER Quinoneacetoxylation 383 TIEMANN Rearrangement 363 Thorpe 153... 

Tiemann rearrangement. Rearrangement of amide oximes (available from nitriles and hydroxyl-amine) to monosubstituted ureas by treatment with benzenesulfonyl chloride and water. 

CCC2767>. Modified Tiemann rearrangement of cyclic amidoxime 0-methanesulfonate afforded the carbodiimide on treatment with NaOH and Aliquat 336 in CHjClj <83JOCi694>. 

A very low yield (1.2%) of benzodiazocinone (12) is obtained as a minor, undesired side product upon rearrangement of the oxime generated in situ from a tetralone derivative (Equation (17)) <86JHC975>. The Tiemann rearrangement allows the preparation of perhydro-l,3-diazocin-2-one (22) <83JOC1694>, while a modification of this rearrangement provides cyclic carbodiimide (7), also prepared by mercuric oxide oxidation of 2-thione derivative (14) (Scheme 12) <83JOCl694>. 

This reaction is related to the Schmidt Reaction and Tiemann Rearrangement. 

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