Chlorination, of alcohols

Pyridylmethyl chloride 11 was obtained by direct chlorination of alcohol 10 using thionyl chloride The hydroxymethyl-pyndine 10, in turn, was synthesized from 3,5-dimethylpyndine in 6 steps utilizing a Boekelheide reaction that transformed the 2-methylpyridine-A -oxide to the corresponding hydroxymethyl-pyridine 10. 

Such chlorination of alcohols has also been observed 100 101 a simple example is the chlorination100 of 2-phenoxyethanol ... 

Bu3PO is also a catalyst for decarboxylative chlorination of alcohols by phosgene (equa-tion 171)1093. 

Pyridylmethyl chloride 11 was obtained by direct chlorination of alcohol 10 using... 

Chloral.—Chloral, or tri-chlor acet-aldehyde, was first prepared by Liebig in 1832 by the chlorination of alcohol as above. It may also be obtained by the direct action of chlorine upon acet-aldehyde. It is an oily liquid with a sweet suffocating odor. It boils at 97.7°. It does not mix with water but on boiling with water it forms a hydrated compound which crystallizes in large clear crystals, readily soluble in water. This is known as chloral hydrate. The structure of chloral hydrate is probably that of an addition product, viz., a, chlorinated di-hydroxy alcohol. In this compound we have an exception to the general rule that two hydroxyl groups can not be linked to the same carbon atom. 

Chlorination of alcohols with trimethylsilyl chloride in the presence of a catalytic amount of bismuth chloride typical procedure... 

Chlorination of alcohols. Bismuth(IlI) chloride is an excellent catalyst for chlorination of alcohols with chlorosilanes. Thus t-butyl chloride is obtained quantitatively at room temperature. 

Some manufacturers have been reported as using ferric chloride to catalyze I the chlorination of alcohol, but water appears to be as effective and offers other advantages. While Eq. (5) may represent the ultimate result, in practice it has been found desirable to add the required water after the chlorination is partially completed. It is also desirable to operate with an excess of chlorine to avoid excessive formation of ethyl chloride. 

The pair of both hexachloroacetone/triphenylphosphine and dichloroselenurane/tri-phenylphosphine" are also applied to the chlorination of alcohol, and the first pair has been extensively studied in the chlorination of allyl alcohol. 

Organic esters, hahdes, and ethers have been used to initiate hving polymerization of IB at temperatures from —90 up to —40 °C. In conjunction with TiCLt, ethers are converted to the corresponding chlorides almost instantaneously, while the conversion of esters is somewhat slow [34]. According to Chen et al. alcohols are inactive with TiCLj alone but have been used in conjunction with BCI3 and TiCLj [43]. The BCI3 converts the alcohols to the active chloride, which is activated by TiCLj. In contrast to Chen et al., Puskas and Grassmuller reported chlorination of alcohols and initiation by TiCLj alone [44]. 

Reactions Acid scavanging -Chlorination of alcohols -Cleavage of ethers -Hydro silylation -Fluorination -... 

Chlorination of alcohols/Cleavage of ethers Polymer synthesis... 

Alkyl Chlorides. Chlorination of Alcohols to give Alkyl Chlorides... 

A practical and convenient route to a number of chlorinated compounds 1300 is the direct chlorination of alcohols 1298 [964]. 

The advantages of the partial chlorination of alcohols (60-95% conversion) with HCl and completion of the chlorination by a catalytic phosgenation and subsequent decarboxylation of the resulting chloroformates have been combined in a two-stage process [974, 982]. Only small amounts of dialkyl ethers, alkenes, isomeric chloroalkanes, or dialkyl carbonates are claimed to be formed as side products. 

FIGURE 9.39 5 2 chlorination of alcohols using thionyl chloride in pyridine. 

Phospholane- and 1,2,3,4,5,6-hexahydrophosphinine derivatives, tetra-hydro- and hexahydrophosphepines, as well as a dibenzophosphole were applied as the P(III)-reactant. The corresponding phosphine oxides formed were reduced by Ph2SiH2 in the course of the reaction. A typical realization using 1-phenyl-dibenzophosphole as the catalyst in the bromination of 2-phenylethanol is shown in Scheme 64. Another group dealing with the catalytic Appel reaction utilized the reagents triphenylphosphine oxide and oxalyl chloride in the chlorination of alcohols (Scheme 65). ... 

Chlorination of alcohols by Thionyl Chloride the preparation of acyl chlorides from lactones and anhydrides, and the bromi-nation and iodination of aromatic rings by Benzyltrimethylammo-nium Tribromide and Benzyltrimethylammonium Dichloroio-date, respectively, are all effectively catalyzed by the presence of ZnCl2. In addition, ZnCl2 acts as a source of chloride for the halogenation of primary, secondary, and allylic alcohols using Triphenylphosphine-DiethylAzodicarboxylate. ... 

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