Ketone, dibenzyl

The dibenzyl ketone has a very high b.p. (ca. 200°/21 mm.) and this remains in the flask when the unsymmetrical ketone has been removed by distillation. The dialkyl ketone has a comparatively low b.p. and is therefore easily removed by fractionation under normal pressure acetone is most simply separated by washing with water. In this way methyl benzyl ketone (R = CHj), ethyl benzyl ketone (R = CHgCH,) and n-propyl benzyl ketone (R = CHjCHjCH,) are prepared. By using hydrocinnamic acid in place of phenylacetic acid ... 

Dibenzyl ketone (l,3-diphenyl-2-propanone) [102-04-5] M 210.3, m 34.0 . Fractionally crystd from its melt, then crystd from pet ether. Stored in the dark. 

The facility with which a-cleavage occurs in solution depends on the stability of ttae adical fragments that can be ejected. Dibenzyl ketone, for exan le, is readify cleav jjiboto-lytically. Similarly, r-butyl ketones undergo a-cleavage quite readify on p ioCo in solution. ... 

Condensation of 2-azido benzonitrile derivatives 703 with ethyl aeetonediearboxylate in presenee of NaOEt gave the triazoloquinoline derivatives 705 presumably through the intermediate 704 (90S654). Reaetion of 703 with dibenzyl ketone gave the triazole 706 aeeompanied by 707 whieh upon treatment with NaH in THF afforded 706 (97S773) (Seheme 122). 

I. 2-Methylcyclohexanol EK Decahydro-2-naphthol A a-Bromo-p-xylene A, EK, MCB Trimethylamine, anhydrous EK Phenothiazine EK, MCB Dibenzyl ketone EK, MCB Triethylamine MCB, EK Olefins A... 

For this preparation Matheson, Coleman and Bell practical grade dibenzyl ketone was recrystallized once from anhydrous ether at —70°. It melted at 33-34°. Practical grade dibenzyl ketone may be used directly however, the yield of the pyranone is somewhat lower. 

Acetic acid, reaction with bicyclo[2.2,1]-hepta-2,5-diene, 45, 74 reaction with dibenzyl ketone, 47, 54... 

Benzy 1 2 carbomethoxycyclopentanone from 2 carbomethoxycyclopentanone and benzyl chloride, 45, 8 2 Benzylcyclopentanone, 46, 7 N Benzyloxycarbonylglycine, 46, 49 Benzyltnmethylammonium hydroxide as catalyst for condensation of benzil with dibenzyl ketone, 46,... 

Dehydrohalogenation, of ,a,-dibromo-dibenzyl ketone, 47, 62 of N,N-dichlorocycIohexylamine to N-chlorocyclohexylideneimine, 46,16... 

DlBENZ[c,e][l,2]AZABOKINE, 5,6-DIHY-DRO-6-METHYL-, 46, 6S Dibenzyl ketone, bromination of, 47, 62... 

Tetramethvlethylene, 47, 36 Tetraphenylcyclopentadienone, from dibenzyl ketone and benzil, 46, 45... 

Tndecanedione, 47, 95 Tnethylamine, 46, 18 dehydrobromination of o-bromo-y-butyrolactone with, 46, 23 dehydrobromination of or.a -dibromo-dibenzyl ketone, 47, 62 dehydrochlormation of cyclohexane-carbonyl chloride, 47, 34 in synthesis of nicotinic anhydride with phosgene, 47, 90 Tnethyl orthoformate, condensation with N,N diphenylethylene-diaminc, 47,14... 

The CIDNP technique has led to similar conclusions about the precursor multiplicity for methyl benzyl ketone (Blank et al., 1971). With dibenzyl ketone and phenyl a-phenylethyl ketone (Closs, 1971a Muller... 

With this reaction available, a simple synthesis of unsymmctrical dibenzyl ketones (21) can be planned. The carbonyl group can be derived from a nitro group (22) by TlClg-catalysed hydrolysis (p T 183 ). Reversing the selective reduction gives (23) and a,6-dlsconnection separates this Into aldehyde (24) and nitro compound (25), available by reduction of (20). 

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