Benzyl chloromethyl ketone

BENZYL CHLOROMETHYL KETONE (2-Propanone, l-chloro-3-phenyl-)... 

Benzyl chloromethyl ketone has been prepared by the reaction of diazomethane with phenylacetyl chloride. The method of Clibbens and Nierenstein, in which one equivalent of diazomethane is added to the acyl chloride and the chloromethyl ketone obtained directly, could not be duplicated by Bradley and Schwarzenbach or by the submitters. 

Observations from both Nierenstein and Robinson have enabled the understanding of this reaction. It is also accepted that excess diazomethane at lower temperatures leads to diazoketones because hydrogen chloride liberated gets consumed by its preferential reaction with excess diazomethane to form methyl chloride 5. This explains why hydrogen chloride gas added through an external source to a solution of diazoketone can drive the Nierenstein to completion. Further evidence to support this theory was offered by McPhee and Klingsberg in the procedure for the synthesis of benzyl chloromethyl ketone from phenylacetyl chloride, by which the diazoketone is separately treated with hydrogen chloride at 0 °C and also by Bhatt et al. in their synthesis of a-chloromethyl-3,4,5-triacetoxy acetophenone in which diazoketone is the key intermediate. ... 

Chloroacetophenone (Mace, 1-chloroacetophenone, -chloroaceto-phenone, CAP, phenyl chloromethyl ketone), a lacrlmator, Is a white volatile crystalline solid with an odor like that of apple blossoms. It Is commonly referred to as CN. It melts at 54°C, bolls at 24S°C, Is slightly soluble In water, and Is soluble In ethanol, benzene, acetone, and benzyl chloride. 0 Its vapors are extremely Irritating to the eyes and skin and may cause permanent Injury to eyes. 

Hydroxymethylation of carbonyl compounds.3 Alkyl chloromethyl ethers react in the presence of Sml2 (2 equiv.) with ketones in THF to give adducts in 50-80% yield. The reaction with aldehydes is conducted in tetraethylene glycol dimethyl ether, which suppresses pinacol reduction. Hydroxymethylation of carbonyl compounds can be effected by use of benzyl chloromethyl ether followed by hydrogenolysis of the adduct. 

A very convenient hydroxymethylation process has been developed based on the Sml2-mediated Bar-bier-type reaction. Treatment of aldehydes or ketones with benzyl chloromethyl ether in the presence of Smh provides the alkoxymethylated products in good to excellent yields. Subsequent reductive cleavage of the benzyl ether provides hydroxymethylated products. Even ketones with a high propensity for enolization can be alkylated by this process in reasonable yields. The method was utilized by White and Soners as a key step in the synthesis of ( )-deoxystemodinone (equation 27). This particular ketone substrate resisted attack by many other nucleophilic reagents (such as methyllithium) owing to conpeti-tive enolate formation. 

HydroxymethyUttion of ketones. A ketone is treated with sodium hydride for conversion into the enolate and this is alkylated with benzyl chloromethyl ether. Dioxane is the preferred solvent since O-alkylation is minimized. The examples formulated illustrate a high degree of stereoselectivity. The benzyl group should... 

The commercial cardo poly(ether ketones) (PEK-C) were selected by Liu et al. to prepare AEMs by usual three-step postmodilication method (Figure 11.8). The final membranes showed ionic conductivity varied from 1.6 to 5.1 mS/cm over the temperature range of 20°C-60°C. Although its ionic conductivity was quite lower compared with other PEEK-based AEMs, the methanol permeability was less than 10" cm% at 30°C in 4 M methanol solutions. Except this way, Zhang and colleagues successfully introduced benzyl chloromethyl groups to the PEK-C matrix via plasma graft polymerization. This approach enables a well preservation in the structure of... 

The chloromethylation can be generally employed in aromatic chemistry benzene, naphthaline, anthracene, phenanthrene, biphenyls and many derivatives thereof are appropriate substrates. The benzylic chlorides thus obtained can be further transformed, for example to aromatic aldehydes. Ketones like benzophe-none are not reactive enough. In contrast phenols are so reactive that polymeric products are obtained. ... 

Dimethylthexylsilyl trifluorometh-anesulfonate, 74 using other methods Allyl chloroformate, 9 Benzyl trichloroacetimidate, 32 Bromodimethylborane, 47 Chloromethyl ethyl ether, 75 2,3-Dihydro-1,4-dioxin, 112 p-Methoxyphenol, 181 of aldehydes and ketones as acetals or dithioacetals... 

KETONE, p-ANISAT, 4-PYRIDYL see MFH930 KETONE, 3-AZABICYCLO(3.2.2)NONYL CHLOROMETHYL see CEClOO KETONE, 3-AZABICYCLO(3.2.2)NONYL lODOMETHYL see IDZIOO KETONE, 1-AZIRIDINYL 3-(BIS(2-CHLOROETHYL)AAnNO)-pMOLYL see BHQ760 KETONE, 1-BENZYL-2-INDOLYL HYDROXYMETHYL- see BES300 KETONE, 5-BENZYLOXY-3-INDOLYL 4-PIPERIDYL see BFC200... 

---