1,1 -dichloromethyl methyl ether

III-G-45. Dichloro(methoxy)methane (Methyl Dichloromethyl Ether, CH3OCHCI2)... 

In the onginal route to isoflurane, the methyl ether of tnfluoroethanol is made with dimethyl sulfate [.S] followed by careful chlorination of the methyl group to make the dichloromethyl ether. This ether is fluorinated with hydrogen fluoride and an antimony catalyst and the final step is monochlorination of the a carbon of the ethyl group [S] (equation 2)... 

Chloromethyl methyl ether may contain 1 to 8% 57/ -dichloromethyl ether as an impurity (Environment Canada, 1993a). 

Chloro-3-hydrox34oluene, see p-Chloro-ro-cresol 2-Chloroisopropyl ether, see Bis(2-chloroisopropyl) ether p-Chloroisopropyl ether, see Bis(2-chloroisopropyl) ether Chloromethane, see Methyl chloride (Chloromethyl)benzene, see Benzyl chloride Chloromethyl bromide, see Bromochloromethane Chloromethyl ether, see sym-Dichloromethyl ether (Chloromethyl)ethylene oxide, see Epichlorohydrin (2-Chloro-l-methylethyl) ether, see Bis(2-chloroisoprop-yl)... 

Dichloroethyl formal, see Bis(2-chloroethoxy)methane Dichlorodiethyl methylal, see Bis(2-chloroethoxy)methane Dichlorodiisopropyl ether, see Bis(2-chloroisopropyl) ether sjm-Dichlorodimethyl ether, see sj jn-Dichloromethyl ether Dichlorodimethylhydantoin, see l,3-Dichloro-5,5-di-... 

Carbon tetrachloride. Chloroform, 2-Chlorophenol, Cyclohexanol, Cyclopentene, 1,1-Dichloroethylene, irans-l, 2-Dichloroethylene, IV.yV-Dimethylaniline, lV,lV-Dimethylformamide, 2,4-Dimethylphenol, 2,4-Dinitrotoluene, 1,4-Dioxane, 1,2-Diphenylhydrazine, Ethyl formate. Formaldehyde, Glycine, Methanol, Methylene chloride. Methyl formate, 2-Methvlphenol. Monuron, 4-Nitrophenol, Oxalic acid, Parathion, Pentachlorophenol, Phenol, l idine. Styrene, Trichloroethylene, Vinyl chloride Formylacetic acid, see cis-l,3-Dichloropropylene, irans-1,3-Dichloropropylene IV-Formylcarbamate of 1-naphthol, see Carbaryl Formyl chloride, see Chloroethane, Chloroform, sym-Dichloromethyl ether, ds-1,3-Dichloropropylene, irans-ES-Dichloropropylene, Methyl chloride. Methylene chloride. Trichloroethylene, Vinyl chloride lV-Formyl-4-chloro-o-toluidine, see Chlornhenamidine. 

Hydracrylic acid, see p-Propiolactone Hydrazobenzene, see Aniline Hydriodic acid, see Methyl iodide Hydrobromic acid, see Bromodichloromethane, Bromoform, Methyl bromide, Metobromuron Hydrochloric acid, see Alachlor. Aldrin, Benzyl chloride, a-BHC, p-BHC, Bis (2-chloroethyl) ether, Bis(2-chloroisopropyl) ether, Bromacil. Bromodichloromethane, Carbon tetrachloride, Chloroethane, Chloroform, o-Chloronitrobenzene. Chloropicrin, Chloroprene, p-Chloronitrobenzene, 2,4-D, see Dalanon-sodium. p.p -DDD, p,p -DDT, Dicamba. 1,1-Dichloroethane, 1,1-Dichloroethylene, fratts-l,2-Dichloroethylene, s/m-Dichloromethyl ether, 2.3-Dichloronitrobenzene. 3.4-Dichloronitrobenzene. 1,2-Dichloropropane, cis-1,3-... 

I CCIsNOj Chloropicrin /CHaCl CHaCl Dichloromethyl ether COClj Phosgene < Cl—COOCCls Diphosgene >< CHj—AsClj Methyl dichloroarsine... 

These compounds are usually prepared by the direct action of the halogens on the corresponding ethers. For example, from methyl ether and chlorine, dichloromethyl ether is obtained ... 

However, in the particular case of the halogenated methyl ethers it is preferable, especially in their industrial manufacture, to commence with formaldehyde (or its polymers) and the hydrogen halide. In this case the reaction takes place in two stages for instance, in the preparation of dichloromethyl ether, chloromethyl alcohol is formed first ... 

Boiling with sodium methylate converts dichloromethyl ether into dimethyl methylal. The reaction apparently takes place in two phases dimethoxy methyl ether is first formed,... 

All the following have been called X-gas di-bromo(di)methyl ether, methylsulphuryl chloride, dibromomethyl ether, dichloromethyl ether, ethyl dibromoarsine, phenyl dibromoarsine, ethyl bromoacetate. 

Chloromethyl dichloromethyl ether, CH2C10CHC12, reacts similarly to di-chloromethyl methyl ether.1123... 

This method is very convenient, requires relatively little time, and gives yields of 70-90%. It can be applied to condensed aromatic systems such as pyrene594 and coronene595 and to ferrocene596 and colchicine.597 Results are equally good when the alkyl dichloromethyl ether is replaced by dichloromethyl methyl sulfide.598 An example is the formylation of veratrole described below, and the same procedure can be used for preparation of mesitylenecarbaldehyde from mesitylene ... 

The 3-0-benzyl-et-D-galactosyl chloride (11) has been synthesized in 80% yield from the corresponding methyl /d-D-galactoside derivative on controlled exposure to dichloromethyl methyl ether with catalytic zinc chloride. Prolonged exposure led to cleavage of the benzyl ether and formation of formate (12) and dichloromethyl ether (13) ... 

Addition of the carbenoids derived from alkyl dichloromethyl ethers to the exo-methyleneketal (81) shows an increasing exo-selectivity as the bulk of the alkyl group increases (cyclohexyl > Bu > n-hexyl, methyl) but the effect is not very marked owing to the remoteness of the alkyl group. 

Gross and Mirsch found that reaction of aromatics with dichloro methyl methyl sulfide and aluminum chloride yield aromatic aldehydes. However, the yields were lower compared to using dichloromethyl ethers as formylating agent. Cumene aldehyde was obtained in a 41%, mesityl aldehyde in 49% and 2-naphthyl aldehyde in 52% yield (Eq 1.16). 

Frontier orbital theory predicts that electrophilic substitution of pyrroles with soft electrophiles will be frontier controlled and occur at the 2-position, whereas electrophilic substitution with hard electrophiles will be charge controlled and occur at the 3-position. These predictions may be illustrated by the substitution behaviour of 1-benzenesulfonylpyr-role. Nitration and Friedel-Crafts acylation of this substrate occurs at the 3-position, whereas the softer electrophiles generated in the Mannich reaction (R2N=CH2), in formylation under Vilsmeier conditions (R2N=CHC1) or in formylation with dichloromethyl methyl ether and aluminum chloride (MeO=CHCl) effect substitution mainly in the 2-position (81TL4899, 81TL4901). Formylation of 2-methoxycarbonyl-l-methylpyrrole with... 

Dichloromethyl methyl ether has been prepared by the chlorination of chlorodimethyl ether in the liquid5-4 or gas phase,5 by the reaction of chlorodimethyl ether with sulfuryl chloride and benzoyl peroxide,6 7 and by the treatment of methyl formate with phosphorus pentachloride.8-10... 

Dichloromethyl methyl ether may be employed preparatively in various ways. Thus it effects the replacement of carbonyl and hydroxyl oxygens by chlorine,11 and may be used in the preparation of a-acetochlorosugars 12 and acid chlorides, particularly those derived from acetylated monocarboxylic acid sugars 12 13... 

Dichloromethyl methyl ether, 47, 47 in preparation of aromatic aldehydes,... 

Phosphorus pentachlonde, for conver sion of d l 10 camphorsulfomc acid to acid chloride, 46,14 reaction with methyl formate to yield dichloromethyl methyl ether, 47, 47... 

Several chlorophyll derivatives have been prepared by electrophilic substitution, inter alia by formylation reactions. Adopting methods from corrin chemistry.50 alkylation with chloro-methyl methyl ether (caution toxic),32k chloromethyl methyl sulfide,51 and dichloromethyl methyl ether (caution toxic)52 in the presence of Lewis acids are the methods of choice to introduce carbon residues into the chlorin frame work. The compounds listed below have been prepared by these methods. 

Besides 11-15-11-17, several other formylation methods are known. In one of these, dichloromethyl methyl ether formylates aromatic rings with Friedel-Crafts catalysts.The Compound ArCHClOMe is probably an intermediate. Orthoformates have also been used. In another method, aromatic rings are formylated with... 

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