Amine reactions with ketone

Dihalo ethers, preparation, 232 Dihalo ketones, preparation, 107 a,a-Dihalo ketones, preparation, 100 a, S-Dihalo ketones, reaction with amines, 730 ... 

Extensive study by several groups showed that Ar—X (X = I, Ts, Br, and Cl) can undergo coupling reactions with amine and ketones in the presence of a... 

The conjugate addition of heteronucleophiles to activated alkenes has been used very often in organic synthesis to prepare compounds with heteroatoms [3 to various activating functional groups, e.g. ketones, esters, nitriles, sulfones, sulfoxides and nitro groups. As in the Michael reaction, a catalytic amount of a weak base is usually used in these reactions (with amines as nucleophiles, no additional base is added). 

An important difference between the monocyclic and benzo-fused series is that reactions with amines do not lead to the corresponding heterocycles in the benzo-fused series. For instance, aminolysis of chromone 9.29 affords phenol 9.30. Benzopyridone 9.32 is not produced. The facile tautomerisation between 9.25 and 9.26 would analogously give ketone 9.31 in this series. This high-energy intermediate is not aromatic, and the reaction stops at phenol 9.30. 

There are many examples of this type of reaction. Reactions with amines go well and the amino-ketone products are widely used in the synthesis of drugs. 

Thioxanthiones (TX) absorb strongly in the near-ultraviolet region of the spectrum, and their reaction with amines comprises a bimolecular initiator system competitive with photodissociative initiators [138 150. The photochemistry and photophysics of TX in the presence of amines are similar to that observed for other aromatic ketones, and can be summarized by the scheme proposed by Davidson [148] (Scheme 17). 

Oximes.—Evidence in favor of the ketone structure is that quinone undergoes the characteristic aldehyde or ketone reaction with hydroxyl amine forming oximes. Furthermore, it forms both a mono- and a... 

Oximes and Hydrazones.—The characteristic aldehyde and ketone reactions with hydroxyl amine and phenyl hydrazine, depending upon the carbonyl group, = C = O, take place with the aromatic aldehydes and ketones just as they do with the aliphatic and yield oximes and hydrazoneSy the former being of especial importance. 

A very useful method leading to highly sterically hindered /3-diketones with R1 = CRR(OMe), employed for the synthesis of alkaline-earth metal-containing molecular precursors for CVD, is based on the condensation of ketones with alkynes, followed by the reaction of the product with acyl chlorides to give a-acetylinic ketones. Finally the a-acetylinic ketones react with amines yielding aminovinylketones and, after hydrolysis, the resulting /3-diketones (Equation (5)) 50... 

Carbonyl difluoride is a particularly versatile fluorinating agent, and an important material for the synthesis of organofluorine compounds [1079], Its reactions with perfluoroalkenes gives perfluoroacyl fluorides in the presence of a fluoride ion source, and its facile reaction with amines or alcohols results in the formation of carbamoyl fluorides or fluoroformates, respectively. The fluorination of carbonyl compounds, such as aldehydes and ketones, with COF can give gem-difluorides by replacement of the carbonyl oxygen atom with two atoms of fluorine e.g.-. 

Pyrones, which are the ring-oxygen equivalents of pyridones, are simply a- and y-hydroxy-pyrylium salts from which an 0-proton has been removed. There is little to recommend that 2- and 4-pyrones be viewed as aromatic they are perhaps best seen as cyclic unsaturated lactones and cyclic p-oxy-a,P-unsaturated-ketones, respectively, for example 2-pyrones are hydrolysed by alkali, just like simpler esters (lactones). It is instructive that, whereas the pyrones are converted into pyridones by reaction with amines or ammonia, the reverse is not the case - pyridones are not transformed into pyrones by water or hydroxide. Some electrophilic C-substitutions are known for pyrones and benzopyrenes, the oxygen guiding the electrophile ortho or para, however there is a tendency for electrophihe addition to the C-C double bond of the heterocyclic ring, again reflecting their non-aromatic nature. Easy Diels-Alder additions to 2-pyrones are further evidence for diene, rather than aromatic, character. 

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