Acetonyl bromide

SYNS ACETONYL BROMIDE ACETYL METHYL BROMIDE BROMOACETONE BROMOACETONE (DOT) BROMOACETONE, Uquid (DOT) BROMO-METHYL METHYL KETONE 1-BROMO-2-PROPAN-ONE MONOBROMOACETONE RCRA WASTE NUMBER POl 7... 

ACETONYL BROMIDE (598-31-2) Forms explosive mixture with air (flash point 113°F/45°C). Violent reaction with strong oxidizers. Decomposes in elevated temperatures above 276°F/136°C, emitting highly toxic fumes of hydrogen bromide. 

Synonyms cas 598-31-7 acetonyl bromide acetyl methyl bromide bromo-2-propanone monobromoacetone... 

When 2-bromobenzoic esters are treated with ir-(2-methoxyallyl)nickel bromide, the acetonyl group is introduced. Reductive cyclization of the methyl 2-acetonylbenzoates yielded isochroman-l-ones (77JOC1329). 

Note Alkylpyrazinium salts (or corresponding ylides) lend themselves to cy-clization or cycloaddition, as typified in these examples. l-Acetonyl-2,3-dfinethylpyrazinium bromide (358) (made in situ) gave 1,8-di-methylpyrrolol 1,2-a pyrazinc (359) (NaHC03, H20, reflux, 30 min 41%) 794 also analogues likewise.328 794 1571... 

Quinolinium ylids react similarly to give 3-nitropyrrolo[l,2-a]quinolines (11) (40-45%) and A-phenacylquinoxalinium bromide gives 3-nitro-2-phenylpyrrolo[l,2-a]quinoxaline 12 (41%).J Neither N-acetonyl- nor N-phenacylpyridinium bromide undergoes cyclization with nitromethane. However, when the pyridine ring carries a nitrile group at the 3-position, a 1-nitroindolizine (13) is formed.1... 

The direct introduction of the two-carbon unit of the heterocyclic ring, ortho to an existing carboxylic acid (ester) can be achieved in two ways ort/io-bromobenzoates can be coupled with 7r-(2-methoxyallyl)nickel bromide for the introduction of acetonyl, or thallation of benzoic acids, ortho to the carboxyl, can be followed by palladium-catalysed coupling with alkenes. Benzoates carrying an ortho acetylenic substituent can be ring closed using mercuric acetate, as shown below." ... 

ACETONYLATION 2-Methoxyallyl bromide. w-(2-Methoxyallyl)nickel bromide. 

Various imidazopyridinium salts were also prepared. 2-AIkylatninO or arylaminopyridines react with a-bromoketones to give 1-alkyl-or 1-aiylimidazo-[l,2-fl]pyridinium salts substituted at position 2. 2-Anilinopyridine (DC-149) and bromoacetone in boiling acetone give the 2-methyl-l-phenylimidazo(l,2-a -pyridinium bromide IX-lSl rather than the 1-acetonyl salt IX-ISO. When... 

Alkylation of 2-methoxypyridine with a phenylacyl bromide or bromoacetone gives Mphenacyl- or 7V-acetonyl-2-pyridone, which can be cyclized in sulfuric acid or perchloric acid to oxazolo[3,2-fl]pyridinium salts (RJ. 1115), which have been isolated as their perchlorates (XII-7SS). ... 

A synthesis of 2-alkyl- or 2-aryl-substituted benzo[Z>]thiophens consists of the cyclization of an aryl thioether with an acetonyl or phenacyl group in the or/Ao-position (315) with 48% hydrobromic acid. In order to obtain (315 R = Ph), 2-methylthiobenzyl cyanide is treated with phenyl-magnesium bromide. The reaction of or//to-methylthiostyrene derivatives, especially cinnamic acids (316), with sulphuryl chloride followed by pyridine, probably gives the benzo[6]thiophens (318) via the sulphenyl chloride (317). ... 

The 2-methoxyallylnickel bromide (CXXIX) serves as a new reagent for the introduction of the acetonyl functional group (Hegedus and Stiverson, 1974). Halides containing both sp - and 5p -hybridized carbons may be used. The reaction is facile and gives exclusively the cross-coupled products... 

CXXX). Reaction of CXXIX and the bromide (CXXXI) affords 6 -acetonyl-papaverine (CXXXII) in 73% yield. 

C9Hi7BrS, trans-1-Thioniabicyclo[4.4.0]decane bromide, 42B, 258 C9H17CIOS, 2-Chloro-4-t-butylthiacyclohexane sulfoxide, 43B, 431 C9H17CIO5S2, 1-Acetonyl-1-thionia-5-thiacyclo-octane perchlorate, 35B, 223... 

Phenacyl- and acetonyl-pyridinium bromide react with benzenediazo-nium cation in the presence of sodium acetate, giving the betaines (43) and their salts s. 

In addition to the successive introduction of the C, and atoms, it is also possible to form an acetonyl residue by alkylating (53) with propargyl bromide and subsequent hydration [102]. 

Finally, achiral phosphonium salts have been explored as Lewis acid catalysts in some other reactions. The examples are briefly listed here but are not discussed in more detail. Phosphonium salts have been used as catalysts for the N,N-dimethylation of primary aromatic amines with methyl alkyl carbonates, giving the products in good yields [78]. Furthermore, acetonyl(triphenyl)phosphonium bromide has been used as a catalyst for the cydotrimerization of aldehydes [79] and for the protection/deprotection of alcohols with alkyl vinyl ethers [80, 81). Since the pKj of the salt is 6.6 [82-85], the authors proposed that alongside to the activation of the phosphonium center, a Br0nsted add catalyzed pathway is possible. 

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