Diacetyl methane

Synonyms Acetylacetone, diacetyl methane, acetyl 2-propanone, 2,4-PD... 

D.55) 2,4-Pentanedione, pentane-2,4-dione, acetylacetone, diacetyl methane [123-54-6]... 

Diacetyl methane. See Acetylacetone Diacetyl peroxide. See Acetyl peroxide Diacetyl tartaric acid esters of mono- and diglycerides... 

Methane, ethene, ethane, propene, acetaldehyde, methyl formate, butene, acetone, furan, dimethyl sulfide, isoprene, isobu-tyraldehyde, diacetyl, methylfuran, and isovaleraldehyde... 

Scheme 13). A possible mechanistic pathway involves imidoyl chloride and nitrilium cation intermediates. A similar reaction of A.A/ -diacetyl-1,2-diaminobenzene and phosphoryl chloride with the 2,2 -diindolyl-methane 12 did form the macrocycle 46, but only in a very low yield12 (Scheme 13). 

GC/MS analysis of PFBOA-derivatives can be performed by either El or chemical ionization. Chemical ionization is performed in positive ion mode (PICI) using methane as a reagent gas. In this analysis, abundant protonated [M + H]+ ion of acetaldehyde-derivatives at m/z 240, diacetyl-mono derivatives at m/z 282 and of internal standard o-chlorobenzaldehyde derivatives at m/z 336, form, and an abundant formation of [M + H—18]+ ion of acetoin-derivatives at m/z 282, is observed. Mass spectra of acetaldehyde, diacetyl monooxime, acetoin and o-chlorobenzaldehyde PFB-derivatives recorded in the PICI analysis of a standard solution are reported in Figure 1.19. 

Figure 1.19 Mass spectra of acetaldehyde PFB-oxime (a), diacetyl mono PFB-oxime (b), acetoin PFB-oxime derivative (c), and o-chlorobenzaldehyde PFB-oxime (d) recorded in the GC/MS analysis of standard solution performed in positive ion chemical ionization mode using methane as reagent gas (reagent gas flow 1 mL/min ion source temperature 200 °C). Flamini et al., (2005) Monitoring of the principal carbonyl compounds involved in malolactic fermentation of wine by synthesis of 0-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine derivatives and solid-phase-microextraction positive-ion-chemical-ionization mass spectrometry analysis, Journal of Mass Spectrometry, 40, p. 1561. Copyright John Wiley Sons, Ltd. Reproduced with permission...

A repeat of Billman s procedure using sodium hydride dispersions with acetanilide and dibromobutane gave a 20% better yield (98%) of N,N -diacetyl-N biphenyl-a,(o-diaminobutane in slightly less time. The acetylated compounds, unless the alkane is methane, are easily hydrolyzed to the amine. 

S.3. 6. Tetramethyl-m8-[4-dimethyl amino-phenylJ-4.4 -diacetyl-pyiro methan.(2.2 ) 26 II 392. 

The A -nitrososulfonamide 70 was shown to be a convenient reagent for radical trifluoromethylation. UV irradiation of lb with 70 in the presence of diacetyl as a sensitizer led to 38b in 51 % yield (Table 1, entry 8). Distinct advantage of this method is easy handling of the solid 70 instead of gaseous CF3I or of the quite unstable bis(perfluoro-aIkanoyl)peroxides. 70 is assessable from trifluoronitroso-methane 69 in a one-pot procedure [35]. Te(CF3)2 was also used as a trifluoromethyl radical source for trifluoromethylation. The reaction proceeded under UV irradiation and led to a 25 1 mixture of pyrroles lb and 2b (Table 1, entry 9) [36]. 

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