Chloromethyl trimethylsilyl ether

Chloromethylation.1 Chloromethyl methyl ether has been generally used for electrophilic aromatic chloromethylation, but it is highly toxic and now considered a carcinogen. Chloromethylation can be effected by use of a trimethylsilyl ether (1) of a chlorohydrin prepared as shown from trioxane and chlorotrimethylsilane in the presence of stannic chloride in chloroform. This reagent, generated in situ, is effective for chloromethylation of styrene in the presence of SnCl4 any excess is easily decomposed by hydrolysis. Bromomethylation is possible by replacement of ClSi(CH3)3 by BrSi(CH3)3. 

N,N-Bis(trimethylsilyl)methoxymethylamine, (CH3)3Si]2NCH20CH3 (1). The reagent is prepared by reaction of chloromethyl methyl ether with lithium bis(trimethylsilyl)amide (86% yield) b.p. 91-92°/86 mm. 

Synthesis of Primary Amines. iV,iV-Bis(trimethylsilyl)-methoxymethylamine, formally a +CH2NH2 equivalent, is obtained in high yield by treating chloromethyl methyl ether with LHMDS. Treatment of the bis-silylamine with organometallic reagents followed by mild solvolysis gives primary amines in good to excellent yield (eq 12). ... 

Related Reagents. Benzyl Chloromethyl Sulfide r-Butyl Chloromethyl Ether 2-Chloroethyl Chloromethyl Ether Chloromethyl Methyl Ether Chloromethyl Methyl Sulfide (p-Methoxy-benzyloxy)methyl Chloride 2-Methoxyethoxymethyl Chloride 2-(Trimethylsilyl)ethoxymethyl Chloride. 

Etherification. The reaction of alkyl haUdes with sugar polyols in the presence of aqueous alkaline reagents generally results in partial etherification. Thus, a tetraaHyl ether is formed on reaction of D-mannitol with aHyl bromide in the presence of 20% sodium hydroxide at 75°C (124). Treatment of this partial ether with metallic sodium to form an alcoholate, followed by reaction with additional aHyl bromide, leads to hexaaHyl D-mannitol (125). Complete methylation of D-mannitol occurs, however, by the action of dimethyl sulfate and sodium hydroxide (126). A mixture of tetra- and pentabutyloxymethyl ethers of D-mannitol results from the action of butyl chloromethyl ether (127). Completely substituted trimethylsilyl derivatives of polyols, distillable in vacuo, are prepared by interaction with trim ethyl chi oro s il an e in the presence of pyridine (128). Hexavinylmannitol is obtained from D-mannitol and acetylene at 25.31 MPa (250 atm) and 160°C (129). 

A — 55 C solution of [(trimethylsilyl)chloromethyl]lithium (theoretically 51 mmol prepared from 51 mmol of (chloromethyl)trimethylsilanc, 56 mmol of. vet-butyllithium and 56 mmol of TMF.DA in 68 mL of TIIF) is treated with 7.47 g (49 mmol) of 4,4.5,5-tetramethyl-2-(2-propeny))-l,3,2-dioxaborolane. The mixture is cooled to — 78 C and then allowed to warm to r.t. overnight. 50 mL of ice-cold 2 M hydrochloric acid are added and the mixture is extracted with three 60-mL portions of diethyl ether/CFI2CI2 (5 1). The extracts are concentrated and the residue distilled yield 6.36 g (54%) bp 52-55 rC/0.7 Torr. 

C6H1402 3-methoxy-3-methylbutanol 56539-66-3 447.15 38.830 1.2 9155 C6H15CIOSi 2-chloromethyl 2-(trimethylsilyl)ethyl ether 76513-69-4 418.15 36.079 2... 

AMINO GROUP Boron trifluoride ether-ate. 1-/-B utyloxy carbony ltriazole-1,2,4. Di-f-butyl dicarbonate. 4-Dimethylamino-1-f-butyloxycarbonyl pyridinium chloride. CARBONYL GROUP Ceric ammonium nitrate. 1,2-Dihydroxy-3-bromopropane. Sodium N-chloro-p-toluenesulfonamide. Thallium(III) nitrate. Trichloroethanol. Trimethylsilyl cyanide. Chloromethyl methyl sulfide. N,N -Diisopropylhydra-zine. Trichloroethanol. 

Acetoxvmelhyl-3-trimethytsity propene (3) A mixture of 20.4 g (0.125 mol) of 2-(chloromethyl)-3-(trimethylsilyl)propene and potassium acetate (49 g, 0.5 mol) in 200 mL of dry DMF is heated at 55-60 rC for 48 h. After being cooled to 20 °C. the reaction mixture is poured into 500 mL of water and extracted twice with 300 mL of F.t20. The combined ether layers are washed twice with 400 mL of water atid dried over MgS04. After filtration and removal of the solvent via a rotary evaporator, the residue is distilled at 6.5 mmHg by using a short-path column and the product is collected at 68 70 C yield 20.97 (90%) of a colorless oil. 

Continuing their studies on acetal glycosides Tietze and coworkers have made various compounds with general structure (9) (R, alkyl or chloromethyl) by treatment of trimethylsilyl tetra-Q-acetyl-/3-D-glucopyranoside with different ketones and (trimethylsilyl)methyl ether. Related aldehyde methyl acetals (10) have been tested as substrates for -D-glucosidase from sweet almond emulsin. Some of the amino-compounds were particularly... 

Silyl enol ethers serve as precursors to a variety of -(substituted methyl) ketones (Scheme 54). Trimethylsilyl trifluoromethanesulphonate catalyses the formation of a-alkoxymethyl ketones from dialkoxymethanes in the presence of a sterically hindered nitrogen base, and titanium tetrachloride catalyses the site-specific ureidoalkylation of silyl enol ethers of cycloalkanones by reaction with chloromethyl carbamates. Mannich dimethylaminomethylation can be... 

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