Benzal acetophenone

Warfarin sodium Benzal acetophenone Alkofanone Benzaldehyde Butalamlne HCI Chloramphenicol Fenipentol Isocarboxazid Oxacillin sodium Penicillin G benzathine Phenylpropanolamine HCI Tripelennamine Benzaldehyde cyanohydrin Ethotoin... 

NAMEOF TARGET PRODUCT (rans-Benzal acetophenone ... 

The P-bromophosphonic acid 136 is unstable in aqueous solution and decomposes slowly with formation of benzal acetophenone, hydrobromic acid, and phosphoric acid. Decomposition is instantaneous in alkaline solution. In contrast, the monophenyl ester of 136, i.e. 137, is stable and can be dissolved without decomposition in aqueous sodium carbonate 91 . 

The acetophenone should be as pure as possible (m. p. 20°). Commercial acetophenone contains variable quantities of impurities which reduce the yield. By distilling commercial acetophenone with the help of a good still-head (preferably under diminished pressure) and using only the fraction which boils at 201-202° (76-77°/io mm.) greater quantities of benzal-acetophenone can be obtained than by using the entire sample. 

Under comparable conditions the submitters found that the corresponding dihydropyran derivatives were similarly obtained by the condensation of acrolein with methyl vinyl ether in 80-81% yield, with ethyl vinyl ether (77-85% yield), with w-butyl vinyl ether (82% yield), with ethyl isopropenyl ether (50% yield), and with w-butyl cyclohexenyl ether (40% yield). Other <, /3-un-saturated carbonyl compounds that have thus been condensed with ethyl vinyl ether are crotonaldehyde (87% yield), meth-acrolein (40% yield), a-ethyh/3-n-propylacrolein (54% yield), cinnamaldehyde (60% yield), /3-furylacrolein (85% yield), methyl vinyl ketone (50% yield), benzalacetone (75% yield), and benzal-acetophenone (74% yield). 

Methylcyclopropane-2-pnenyl, methyIcyclopro-pane-2-ieopropyl and 1,2. diphenylcyclopropane have beet, i repared by the same sort of reaction as was ussd fox taking phenyIcyclopropane. The starting point was oenralacetone.isobutylideneacetone and benzal-acetophenone respectively and the resulting pyrazo-ler.es rad the following formulas ... 

Nitromethane 2a (1.2 mmol), alumina (1 g, basic activated at 200 °C) and benzal-acetophenone 1 (1.2 mmol) were mixed together without solvent in an Erlen-meyer flask and placed in a commercial microwave oven (operating at 2450 Hz frequency) and irradiated for 18 min. The reaction mixture was allowed to reach room temperature and extracted with chloroform. Removal of solvent and the re-... 

BiX mediates the Mukaiyama-Michael addition of a./i-urisaluraled carbonyl compounds (Scheme 14.87) [171, 172 b, c]. The BiCb-catalyzed Michael addition of 1,3-dicarbonyl compounds to methyl vinyl ketone and benzal acetophenone proceeds efficiently under microwave irradiation [179]. The Knovenagel condensation of aldehydes with active methylene compounds can also be promoted by BiCl3 (Scheme 14.88) [180]. 

Phosphorus trichloride, benzal acetophenone (phenyl styryl ketone) and acetic anhydride react at room temperature forming acetyl cliloride and a compound which yields a ketophosphinic acid with water. The intermediate product is a thick oil, supposed to be a mixture of the acid chloride I and the acid anhydride II, both of which are decomposed by water to form the phosphiiiic acid ... 

CHa.CO.CgHg.—This acid occurs when the phenyl p-methoxysUnyd ketone in the preceding preparation is replaced by phenyl st Tyl ketone (benzal acetophenone). The product contains 0-75 molecule of water of crystalhsation, which is lost at 116° C. when the compound melts. 

The addition of phenyldichlorophosphine to phenyl styryl ketone (benzal acetophenone) in acetic acid solution yields exactly the same types of compounds as are obtained by the use of phosphorus trichloride (p. 127). The structure of the various compounds is proved as before by resorting to bromination. The product... 

These two isomeric bromine compounds are stereoisomers and not structural isomers, since they are both decomposed by alkaline reagents with the formation of benzal acetophenone. The lower-melting isomer may be transformed into the higher-melting one by the prolonged action of sunlight on its chloroform solution. 

Diphenyichloropliospliiiic reacts witli benzaideliyde and with benzal-acetophenone (phenyl styryl ketone) in the presence of j lacial acetic acid according to the schemes ... 

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