Hydrogen chloride with alcohols

The sequence of events is much more complicated than shown and depends on the order and rate of mixing of the reagents. Association of the liberated hydrogen chloride with alcohol will reduce electron density on oxygen, hence the probability of the four-center approach, but the quantitative effect will depend on the nature of R and on experimental conditions such as temperature. The main intervention of hydrogen chloride is the formation of alkyl chloride. See Gerrard and Hudson for details and complete literature citation. 

Glycine ethyl ester hydrochloride has been prepared by the action of absolute alcohol and hydrogen chloride on glycine from glycyl chloride and alcohol by the action of ammonia or hexamethylenetetramine on chloroacetic acid, and subsequent hydrolysis with alcoholic hydrochloric acid and by the action of hydrogen chloride and alcohol on methyleneamino-acetonitrile. ... 

An acid-catalyzed substitution of a 6-oxo group on 2-aminopteridine-4,6-dione with hydrogen chloride in alcohols (65-100°, 3 hr, 80% yield) represents a convenient synthesis of the 6-alkoxy analogs. The reaction proceeds also with pteridine-2,4,6-trione and its 1-methyl and 1,3-dimethyl derivatives. While methoxylation of 2,4,7-trichloro-quinoline gives about equal amounts of 2- and 4-substitution, acid-catalyzed hydrolysis gives specific reaction at the 2-position only. ... 

Ethyl a-phenylacetoacetate can be prepared by the hydrolysis of a-phenylacetoacetonitrile in absolute alcohol with dry hydrogen chloride.1 The present method differs in specifying neutralization of the hydrogen chloride with sodium carbonate and hydrolysis of the imino ether in aqueous sulfuric acid, so that the product separates as fast as it forms, thus being protected from further decomposition, with a considerably increased yield as the result. 

Disilenes readily add halogens14,66 and active hydrogen compounds (HX), such as hydrogen halides,63,66 alcohols, and water,27 63 as well as hydride reagents, such as tin hydride and lithium aluminum hydride.66 These reactions are summarized in Scheme 9. The reaction of the stereo-isomeric disilene (E)-3 with hydrogen chloride and alcohols led to a mixture of E- and Z-isomers, but the reaction with chlorine gave only one of the two possible stereoisomers, thus indicating that the former two reactions proceed stepwise while the latter occurs without Si—Si rotation. 

The regioselectivity of ring opening of 4a-c is successfully controlled by the choice of reaction conditions. Lewis acid in dichloromethane and hydrogen chloride in alcohol are suitable conditions for generation of an alkylideneallyl cation, which was employed for studying its reactivity with nucleophiles such as... 

If the reaction is carried out in the presence of an alcohol and gaseous hydrogen chloride, with water excluded, then 17/3-(r-alkoxyethyIidenamino) steroids are obtained in good yield.47 These can be hydrolyzed reductively to the 17/ -amine with sodium amalgam or zinc amalgam.49... 

CH OH - CHOH CH Cl. which is made by reaction of hypochlorous acid and allyl alcohol with barium hydroxide. With hydrogen chloride, glycide alcohol yields epichlorohydrin... 

By treatment with hydrogen chloride, isoaniyl alcohol is converted to the monochloride, and the vapour of this when acted upon by chlorine gas leads to the formation of three isoaniyl diclilorides (CHa)jCH.CH.,.Cn.iOH + HC1 = (CH XiH.CH-.CILCl + H.,0... 

Trimethylchlorosilane reacts with alcohols or phenols much more slowly, and at certain quanitities of phenol or alcohol does not participate in the reaction altogether. Methyl alcohol cannot be used to separate azeotropic mixture, because in this case there is an active secondary reaction between methyl alcohol and liberated hydrogen chloride with the formation of methylchloride and water. Water hydrolyses the reaction prod-... 

The periodic production of tetrabutoxytitanium (Fig. 90) comprises three main stages the etherification of titanium tetrachloride with butyl alcohol the neutralisation of hydrogen chloride with ammonia the distillation of the excess of butyl alcohol and the filtering of the finished product. 

The Isolation Technique Chromatography. Two alternatives are possible either to isolate the primary Hilbert-Johnson intermediates, i.e., l-peracylglycosyl-4-alkoxy-2(lH)-pyrimidinones, or to treat them with alcoholic hydrogen chloride or alcoholic ammonia and separate the corresponding A-l-glycosyl derivatives of uracil or cytosine. The latter alternative has been used by the earlier authors more frequently because of the higher crystallization ability of... 

N-Protective group. Zervas introduced use of the reagent for the N-protection of amino acid esters, including the activated p-nitrophenyl esters of use in peptide coupling. When required, the protective group is split by treatment with the theoretical amount of hydrogen chloride in alcohol. 

Treatment of 14-hydroxydihydrocodeine-B with thionyl chloride results only in chlorination of the aromatic nucleus (cf. the corresponding reaction with the four dihydrocodeine isomers, Chap. IV), but treatment with phosphorus pentachloride affords 14-hydroxy-6-chlorodihydrocodide [xrx], That the hydroxyl group at C-6 is the one that is replaced by chlorine is revealed by the fact that reduction of [xrx] by sodium amalgam and alcohol is attended by rupture of the cyclic ether link, giving 14-hydroxydihydrodesoxycodeine-C [xx], which is readily reduced catalytically to 14-hydroxytetrahydrodesoxy-codeine [xm]. All attempts to reduce [xrx] to a non-phenolic base, or to secure elimination of hydrogen chloride with production of a substance of the desoxycodeine-C type failed [6]. 

During work on the chemistry of penicillin a variety of methods were developed for the synthesis of 5-aminooxazoles. It has been found that cycloisomerization of acylaminocyanoacetic esters (135) by treatment with hydrogen chloride (in alcohol, ether or acetone), phosphorus pent-oxide, or pentachloride leads to 5-aminooxazole-4-carboxylic esters (136),2 61 which have also been obtained by dehydration of acylamino-malonamic esters (137) with phosphorus oxychloride.2... 

---