1,1 -dichloromethyl chloride

Dichloromethyl)benzene and (tnchloromethyl)benzene arise by further side chain chlo rmation of benzyl chloride... 

Benzal chloride [(dichloromethyl)benzene, a,a-dichlorotoluene, benzylidene chloride], C H CHCl, is a colorless Hquid with a pungent, aromatic odor. Benzal chloride is insoluble in water at room temperature but is miscible with most organic solvents. 

It would appear that this type of addition may not be confined to the addition of NH2 in liquid ammonia, since it has been observed that treatment of 2-chloro-3-dichloromethyl-pyrazine with an excess of methoxide results in the introduction of a methoxy group into the 6-position of the pyrazine ring (Scheme 9) (68TL5931). This reaction is best rationalized in terms of addition of the methoxide ion at the 6-position, followed by loss of chloride ion from the dichloromethyl side chain. 

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... 

DICHLOROISOPROPYL ETHER see CHLOROHETHYL ETHYL ETHER DICHLORQHETHANE see METHYLENE CHLORIDE DICHLOROMETHYL ETHER see BIS (2-CNLOROMETHYL) ETHER... 

Diakyl carbamyl chlorides Diakyl aluminum hydrides Diborane Dibromoketone Dichloromethyl chloroformate Diphosgene Fuming nitric acid Gngnard reagents Hydrides nonvolatile... 

Elimination of hydrogen chloride from 1,1-dichloromethyl sulfide with potassium tcrt-butoxide affords chloromethylthiocarbene [J] (equation 5)... 

The Ciamician-Dennstedt reaction can be thought of as the complement to the Reimer-Tiemann reaction (Scheme 8.3.2). The first step of both reactions is cyclopropanation of one of the carbon-carbon double bonds of a pyrrole with a dichlorocarbene, resulting in intermediate 3. The Ciamician-Dennstedt reaction results from cleavage of the internal C-C bond and elimination of chloride (path a), while the Reimer-Tiemann reaction results from cleavage of the exocyclic bond, and subsequent hydrolysis of the dichloromethyl moiety to furnish aldehyde 5 (path b). 

Furthermore they claimed that the dichloromethyhndolenine 17 could be converted into the quinohne 18 by hot ethanolic sodium ethoxide. They also reported other similar cases of ring expansion of the dichloromethyl bases, with loss of hydrogen chloride, on further treatment with sodium ethoxide (cf. ref. 67). They considered that chloroform acted like a simple alkyl halide giving jS-alkylation of the... 

A solution of 72 g. (0.60 mole) of mesitylene in 375 ml. of dry methylene chloride is placed in a 1-1. three-necked flask equipped with a reflux condenser, a stirrer, and a dropping funnel. The solution is cooled in an ice bath, and 190 g. (110 ml., 1.0 mole) of titanium tetrachloride is added over a period of 3 minutes. While the solution is stirred and cooled, 57.5 g. (0.5 mole) of dichloromethyl methyl ether2 is added dropwise over a 25-... 

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... 

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... 

Chiral (2 )-(Z)-l-methyl-2-butenylboronate 13 was synthesized by way of a-chloroethylboronate 12,0. This route, in which the dichloromethyl starting material is first alkylated with methyllithi-um and then 12 is treated with (Z)-2-propenyllithium, was developed since a-chloro-2-butenyl-boronates such as 7 and 15 are sensitive to racemization, owing to the presence of nucleophilic chloride ions, during the reactions of (4f ,5/ )-2-(dichloromethyl)-4,5-dimethyl-l,3,2-dioxa-borolane and (Z)- or ( )-2-propenyllithium. The route to 13 may be performed as a one-pol operation with an overall yield of >90%. The diastereomeric purity of 13 was estimated to be >98% based on a subsequent reaction with benzaldehyde. 

As has been mentioned in an earlier section, aqueous chlorination of sulphoxides leads to sulphones. If excess reagents are used, sulphonyl chlorides may be formed directly from sulphoxides in good yields (equation 75)89,90,193. In order for this reaction to be synthetically useful, the sulphoxide used should be symmetrical. The product is presumably formed in a stepwise manner via the sulphinyl chloride [RS(0)C1] and the sulphinic acid [RS(0)0H]. In the case of chloromethyl dichloromethyl sulphoxide, the only sulphonyl chloride formed is chloromethanesulphonyl chloride (equation 76) and this may be readily separated from the other products by distillation90,193. Similarly, oxidation of dichloromethyl methyl sulphoxide and methyl trichloromethyl sulphoxide with chlorine in aqueous acetic acid leads to the formation of methanesulphonyl chloride in 75% and 86% yields respectively. Other species are also produced but these are much more volatile and thus easily removed (equations 77 and 78). In the absence of acetic acid the yields are somewhat reduced. 

Hexamethyldisiloxane 7 can, furthermore, be used to transform aromatic tri-chloro- or dichloromethyl compounds such as 87 and 89, in nearly quantitative yield, into the corresponding acid chlorides, for example 88 [110], or aldehydes, for example 90, with formation of trimethylchlorosilane 14 [111] (Scheme 2.17). 

Also reported as a mixture with Dichloromethyl chloroformate (C13-A018) Stannic chloride. 

Tabushi reported that dichlorocarbene CC12 reacts with benzyl alcohol to form an O-H insertion product, i.e., benzyl dichloromethyl ether as the primary product, which undergoes a further base-catalyzed elimination reaction to give benzyl chloride as the final product (Scheme 3, Eq. I).14 In contrast to this... 

Nevertheless, another possibility remained for the formation of insertion products, that they might be formed from the O-H insertion product, e.g., dichloromethyl benzyl ether 5, by the Wittig rearrangement of dichloromethoxy-carbanion 4, (Scheme 5, Eq. I).17 However, treatment of independently prepared benzyl dichloromethyl ether 5 with the same base solely gave benzyl chloride, but the insertion product was not obtained (Eq. 2). Hence, a Wittig-type rearrangement process was excluded. 

This reactivity enables t/tro-substitution to be carried out at a specific position in the ring, irrespective of the presence of other contra-directing groups, and it allows the reaction to be carried out under mild conditions, or with weak electrophiles such as diazonium ions.2 Recent additions to the extensive list of electrophiles that have been used are toluene />-sulfonylisocyanate and ethoxycarbonyl isocyanate (Equation (53)),176 sulfonyl chloride,177 arene178 and silane sulfonyl chlorides,179 and dichloromethyl methyl ether (Equation (54)).1... 

An improved synthesis of dichloromethylenetriphenylphosphorane has been reported.2 It can be isolated from the reaction of (dichloromethyl)triphenylphos-phonium chloride with an excess of bis(triphenylphosphoranylidene)methane provided a solvent is used which is unable to donate a proton to the strongly basic ylide.3... 

The boronic acid ester B was synthesized by transesterification of the corresponding pinacolester A with (lR,2R)-l,2-dicyclohexyl-l,2-dihydroxyethane. Stereoselective chlorination of B was carried out with (dichloromethyl) lithium and zinc chloride. Reaction of the obtained chloroboronic ester C with lithio 1-decyne followed by oxidation of the intermediate D with alkaline hydrogen peroxide afforded the propargylic alcohol E. Treatment with acid to saponify the tert-butyl ester moiety and to achieve ring closure, produced lactone F. Finally, Lindlar-hydrogenation provided japonilure 70 in an excellent yield and high enantiomeric purity. 

Anticipated products from the reaction of sym-dichloromethyl ether with ozone or OH radicals in the atmosphere, excluding the decomposition products formaldehyde and HCl, are chloromethyl formate and formyl chloride (Cupitt, 1980). 

Source 5// -Dichloromethyl ether may form as an intermediate by-product when form aldehyde reacts with chloride ions under acidic conditions (Frankel et al, 1974 Ton and Kallos, 1974a Travenius, 1982). Tou and Kallos (1974) reported that the reactants (formaldehyde and chloride ions) must be in concentrations of mg/L to form 5// -dichloromethyl ether at concentrations of pg/L. 

Formaldehyde reacted with hydrogen chloride in moist air to form 5ym-dichloromethyl ether. This compound may also form from an acidic solution containing chloride ions and formaldehyde (Frankel et al, 1974 Travenius, 1982). In an aqueous solution at 25 °C, nearly all the formaldehyde added is hydrated forming a gem-diol (Bell and McDougall, 1960). May polymerize in an aqueous solution to trio methylene (Hartley and Kidd, 1987). 

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)... 

Dichloromethane, see Methylene chloride Dichloromethyl ether, see sjm-Dichloromethyl ether Dichloromethylmethane, see 1,1-Dichloroethane Dichloromonoflnoromethane, see Dichloroflnoromethane... 

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