Hydrogen Chloride in Methyl Alcohol

The first product of the ester interchange is another orthoester which, on further methanolysis, gives a partly acetylated sugar with free hydroxyl groups at positions 1 and 2, and trimethyl orthoacetate. 

In the presence of a sufficient quantity of water, the first product may suffer hydrolysis into the partly deacetylated sugar, methyl acetate and methyl alcohol. Of course, the reagent may contain enough water for a direct hydrolysis, the rate of which, however, will be slower in such aqueous alcoholic medium, than in pure aqueous hydrochloric acid.  

However, in the pentose series not all of the normal acetylglycosyl halides have a like configuration on the first carbon atom. This follows from the fact that in the arabinose-ribose epimeric pair it is the ribose and not the arabinose which has orthoester derivatives. Consequently, in the normal halides of these two pentoses, the halogen atoms must occupy the left side positions of the first carbon atoms and the names of these substances are, respectively, l,2- mns-2,3,4-triacetyl-D-ribosyl halide and l,2-cf -2,3,4-triacetyl-D-arabinosyl halide. 

The same situation prevails regarding the positions of the halogen atoms in the two acetylheptosyl halides which have so far been investigated the halogen atoms occupy the left sides of the first carbon atoms. 

Regarding the orthoester formation in the ketose series, any acetyl-ketosyl halide may give at least a 1,2-orthoester because the acetyl group at position 1 is always free to approach, from the opposite side, the halogen atom at position 2 in either modification of the halide. 

However, it should be noted with great interest that in the case of the acetyl-D-(a)-glucoheptosyl chlorides it is the unstable form which gives an orthoester. The normal form, therefore, must have the halogen atom on the right side of the first carbon atom and thus be a 

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Methods of Formation.—Only one method has been used for the synthesis of 3,5,6-trimethyl-D-glucose, which has not yet been prepared in crystalline form. The method, published in 1913 by Irvine and Scott,20 entails methylation of 1,2-isopropylidene-n-glucofuranose and hydrolysis with 0.5% hydrogen chloride in aqueous alcohol of the resultant 1,2-iso-propylidene-3,5,6-trimethyl-D-glucofuranose. Modifications introduced... 

The solubility of potassium chloride in ethyl alcohol of sp. gr. 0"939 rises from 4-0 at 0° to 118 at 60°. Similar results are obtained with other mixtures of alcohol and water. According to C. A. L. de Bruyn,32 100 grms. of 98 per cent, methyl alcohol dissolve T22 grms. of sodium chloride, and 14 grms. dissolve in 40 per cent, methyl alcohol 100 grms. of propyl alcohol of sp. gr. 0"816 dissolve 0033 grm. of sodium chloride at room temp., while potassium chloride is almost insoluble in this menstruum, and luminescence occurs when soln. of hydrogen chloride in propyl alcohol are treated with potash lye.33 At 17°, 100 mols. of acetic ether dissolve 0"31 mol. of sodium chloride, and at 40°, 0-037 mol. 

To a known quantity of trichloronitrosomethane is added a solution, saturated at ordinary temperature, of hydrogen sulphide in methyl alcohol (0-25 gm. H S in 10 ml. alcohol at 15° C.), 10 ml. being added for each gramme of trichloronitrosomethane. The mixture is allowed to stand for several hours in a closed vessel until the blue colour of the nitroso compound disappears. If excessive heating takes place during this time, the vessel should be occasionally cooled by immersion in cold water. At the end of the reaction the product is treated with water and filtered from sulphur. It is then extracted with ether, dried over calcium chloride and distilled under reduced pressure. The oxime distils between 50° and 70° C. at 20 mm. of mercury. 

This derivative is obtained by condensing 3-amino-4-hydroxyphenyl-arsine with bismuth chloride in methyl alcohol solution in the presence of hydrogen chloride. It is a black powder, decomposing in a similar manner to the preceding compound, and even boiling its aqueous solution leads to decomposition. 

In the first process, the products are gaseous methyl chloride with unreacted hydrogen chloride and methyl alcohol and several by-products. These are removed in a series of chemical purification steps, and the methyl chloride gas is compressed and dried. A small amount of air remaining in the condensate is distilled off before the liquid is charged into the shipping container. 

When dextrose is heated with methanol containing a small amount of anhydrous hydrogen chloride, a-methyl-D-glucoside is obtained in good yield and can be isolated by crystallization. Similar reactions occur with higher alcohols, but the reaction products are more difficult to isolate by crystallization. Dextrose reacts with acid anhydrides in the presence of basic catalysts, yielding esters. Complete reaction gives the pentaacylated derivative. 

When oxonitine is digested with hydrogen chloride, 6 per cent., in methyl alcohol at 100°, it loses carbon dioxide and is converted into a base, 31 45010 3JH47O43N, m.p. 250°, which contains one methylimino... 

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. ... 

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