174869-08-0

Basic information

• Product Name: α-(3-oxobutyl)-4,4'-dichlorobenzoin
• Synonyms: α-(3-oxobutyl)-4,4'-dichlorobenzoin
• CAS NO: 174869-08-0
• Molecular Weight: 351.229
• Mol File: 174869-08-0.mol

Chemical Properties

• CAS DataBase Reference: α-(3-oxobutyl)-4,4'-dichlorobenzoin(CAS DataBase Reference)
• NIST Chemistry Reference: α-(3-oxobutyl)-4,4'-dichlorobenzoin(174869-08-0)
• EPA Substance Registry System: α-(3-oxobutyl)-4,4'-dichlorobenzoin(174869-08-0)

Safety Data

• Hazardous Substances Data: 174869-08-0(Hazardous Substances Data)

Upstream product

• 4254-20-0 4,4'-dichlorobenzoin 
• 78-94-4 methyl vinyl ketone 
• 3457-46-3 4,4'-dichlorobenzil 

Downstream Products

• 53842-12-9 1-(p-chlorophenyl)-1,4-pentanedione 
• 104-88-1 4-chlorobenzaldehyde 

Relevant articles and documents

Carbon-carbon bond cleavage of α-substituted benzoins by retro-benzoin condensation; A new method of synthesizing ketones

When α-benzylbenzoin (3a, α-benzyl-α-hydroxybenzyl phenyl ketone) was treated with potassium cyanide (1) in N,N-dimethylformamide at 80°C for 1h, the carbon-carbon bond was cleaved, resulting in the formation of deoxybenzoin (4a, benzyl phenyl ketone) and benzaldehyde (2a). This carbon- carbon bond cleavage proceeds through a retro-benzoin condensation mechanism. This method of synthesizing ketones was applied to several α-substituted benzoins (3), and the corresponding ketones (4) were formed in good yields. Further, we found that the cyanide ion-donating ability of tetrabutylammonium cyanide (6, Bu4NCN) is more effective than that of potassium cyanide (1, KCN). As expected from the chemical analogy between cyanide ion and azolium ylide, several azolium salts (7) can also be employed in the retro-benzoin condensation as catalysts. The benzoin derivatives 3 were synthesized in the following three ways; reaction of alkyl halide (9) with benzoin (5), Michael addition of benzoin (5) with acceptors (10), and Grignard reaction of benzils (8). Alkylation of the benzoins without isolation, followed by carbon-carbon bond cleavage, readily afforded the corresponding ketones (4).

Synthesis of ketones by retro-benzoin condensation catalyzed by potassium cyanide

The treatment of 2-benzyl-1,2-diphenyl-2-hydroxyethanone (3a, benzylbenzoin) with potassium cyanide in DMF gave deoxybenzoin (4a). The formation of deoxybenzoin (4a) proceeds through retro-benzoin condensation by catalytic action of cyanide ion. Similarly, retro-benzoin condensation applied to several substituted benzoins 3 resulted in the formation of the corresponding ketones 4 in excellent yields.