Polonovski

Acylation. Aliphatic amine oxides react with acylating agents such as acetic anhydride and acetyl chloride to form either A[,A/-diaLkylamides and aldehyde (34), the Polonovski reaction, or an ester, depending upon the polarity of the solvent used (35,36). Along with a polar mechanism (37), a metal-complex-induced mechanism involving a free-radical intermediate has been proposed. 

A kind of modification of the Polonovski-Boon synthesis is the reaction of 5,6-dihalopyrimidines with ethylenediamine derivatives. Depending on the bulkiness of the amino substituents a more or less regiospecific condensation may proceed (71CB780), as shown recently in the reaction of 5-bromo-6-chloro-l,3-dimethyluracil (279) with 2-methyl-amino- -propylamine to form l,3,5,6-tetramethyl-5,6,7,8-tetrahydrolumazine (280 equation 99) (80Ba3385). 

POLONOVSKY N-oxide Rearrangement Conversion of heterocyclic N-oxIdes to a-acetoxyheterocycles... 

M. and M. Polonovski have shown that Hesse s (1893) bellatropine is a mixture of bases, of which chlorotropane is the chief component. 

M. and M. Polonovski found that when scopolamine is treated with hydrogen peroxide, there is formed in addition to scopolamine iV-oxide [a]i, — 14° (H2O), [B. HBr, m.p. 153°] the quaternary base scopinium, isolated in the form of its bromide, m.p. 209-10°. The latter is reduced by sodium amalgam to a tertiary base, stereoisomeric with scopine and related to the latter as -tropine is to tropine and, therefore, named -SCOPINE. It yields crystalline salts B. HCl, m.p. 257-8°, aurichloride. 

The indolinol character of eseretholemethine is indicated by the fact that the methiodide on treatment with picric acid yields a diquaternary pierate (m.p. 170°) with the loss of the hydroxyl group. More definite proof is afforded by the oxidation of eseretholemethine with ammoniaeal silver nitrate or potassium ferricyanide, when a dehydroeseretholemethine (oxyeseretholemethine of Polonovski), pierate, m.p. 199°, is produced which is assumed to have formula (VI), since on exhaustive methylation it yields trimethylamine and an unsaturated product (deep-red pierate, m.p. 103°), which absorbs two atoms of hydrogen, forming 5-ethoxy-l 8-dimethyl-S-ethyl-2-indolinone (VII), colourless cubes, m.p. 68°. The... 

XXXVIII), m.p. 128°, identical with the product obtained from physostigmine (XXXIX), and, as the latter had already been synthesised from 1-eseroline by Polonovski and Nitzberg,i the work of the American authors constituted the first complete synthesis of physostigmine. 

Constitvtion of Pilocarpine and isoPilocarpine. Though numerous interesting observations have been made on these two alkaloids by M. and M. Polonovski, knowledge of their constitution is due principally to the work of Jowett and of Pinner. ... 

Several groups have contributed pieces to the puzzle of how this reaction proceeds and understanding of the events that transpire has evolved with time. While on the surface, this reaction looks analogous to the Polonovsky reaction (5 —> 6) or the Pummerer... 

Lormetazepam (84) is readily synthesized by Polonovski rearrangement of benzodiazepine oxide derivative by heating with acetic anhydride followed by saponification of the resulting rearranged ester.The mechanism of this rearrangement to... 

The pyrimido[5,4-(/J[2]benzazepine 7-oxide 11 (see Section 3.2.1.5.2.) undergoes a Polonovski rearrangement in hot acetic anhydride to yield the 5-(acetoxy)-5//-pyrimido[5,4-r/] [2]benzazcpine 12, which on hydrolysis gives the 5-hydroxy derivative 13.180... 

A very surprising sulfone formation has been investigated by Oae and coworkers . On heating p-toluenesulfinic acid with dimethylaniline in ethanol for 15 h, the reaction mixture shown in equation 100 has been obtained. Obviously, the observed products arise from an equilibrium between the sulfinic acid and its pseudo-anhydride (disulfide trioxide), which is able to attack the amine nitrogen and degrade the tertiary amine corresponding to a Polonovsky reaction . 

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