Methyl sulphate—

Experiments involving the use of dimethyl sulphate should be carried out by students only under immediate supervision. Not only is the vapour of dimethyl sulphate highly poisonousy but the cold liquid itself is absorbed easily through the skin, with toxic results individual susceptibility to ditnethyl sulphate poisoning varies and may be very high. If the sulphate is splashed on to the hands, wash immediately with plenty of concentrated ammonia solution in order to hydrolyse the methyl sulphate before it can be absorbed through the skin (see p. 528). 

Pure -xylene may be prepared from p tolyl-sodium and methyl iodide or methyl sulphate. 

Methyl sulphate on the skin. Wash immediately and liberally with concentrated ammonia solution, and then rub gently with wads of cotton wool soaked in concentrated ammonia solution. 

A third synthesis which has resulted in the preparation of rieinine and a number of its derivatives is due to Schroeter, Seidler, Sulzbacher and Kanitz,i2 who foimd that cyanoacetyl chloride polymerises spontaneously to 6-chloro-2 4-dihydroxy-3-cyano-pyridine. The di-sodium derivative of this with methyl sulphate produces A -methyl-6-chloro-4-hydroxy-3-cyano-2-pyridone (6-chlororicininic acid), the mono-sodium derivative of which, with methyl bromide or sulphate, is converted into 6-chlororicinine and the latter is reduced by zinc and sulphuric acid to rieinine. A fourth synthesis, starting from 3-nitro-4-pyridone, is due to Reitmann. ... 

Pellotine and Anhalonidine. The A -acetyl derivative of mezcaline (I NHj— NHAc), on treatment with phosphoric oxide, yields 6 7 8-trimethoxy-l-methyl-3 4-dihydrowoquinoline (picrate, m.p. 181-2°), which, on successive catalytic hydrogenation and treatment with methyl sulphate, yields 6 7 8-trimethoxy-l 2-dimethyl-l 2 3 4-tetrahydro-isoquinoline identical with 0-methylpellotine (picrate, m.p. 167-8°), whence it appears that pellotine must be a dimethyl ether of 6 7 8-trihydroxy-1 2-dimethyl-l 2 3 4-tetrahydrowoquinoline. Pellotine and anhalonidine on complete methylation yield the same product, and as anahalonidine is a secondary base and differs from pellotine by containing —CHj less, it must be a dimethyl ether of 6 7 8-trihydroxy-l-methyl-1 2 3 4-tetrahydrowoquinoline, and pellotine should be A -methyl-anahalonidine. 

The three alkaloids concerned, morphine, codeine and thebaine, all behave as tertiary bases. Morphine contains two hydroxyl groups of which one is phenolic and the other a secondary alcohol group. On methylation of the phenolic hydroxyl codeine results. On oxidation, codeine is transformed into codeinone by conversion of the secondary alcohol group into a carbonyl group, and when thebaine is boiled with A-sulphuric acid for a few minutes, it is hydrolysed into codeinone and methyl sulphate, and in other ways thebaine has been shown to contain two methoxyl groups. That the relationship between the three alkaloids is close may be illustrated by the following slightly extended formula —... 

Methylation of the Alkaloids. When cephaeline is treated with methyl sulphate or sodium methyl sulphate under various condition, there is formed in addition to emetine (which was first shown to be the methyl ether of cephaeline and partially synthesised in this way by Carr and Pyman in 1913), more or less N-mcthylcephaeline (wedge-shaped plates, m.p. 194 5°), and N-methylemetine. The latter is also obtained by direct methylation of emetine it is amorphous, [a]n — 52-6° (CHCI3), but yields a hydrobromide, C33H42O4N2.2HBr. 3H2O, m.p. 210-30°, [ajp + 5-6° (H2O). 

Ewins has synthesised both substances from m-methoxybenzoic acid, which on nitration gave 2-nitro-3-methoxybenzoic acid, and this, on reduction and treatment with methyl iodide, yielded damasceninic acid, which, by esterification with methyl alcohol, furnished damascenine. Kaufmann and Rothlen found that the additive product of 8-methoxy-quinoline and methyl sulphate, on oxidation with permanganate, yields formyldamasceninic acid, MeO. CgH3(NMe. CHO). COOH, which can be transformed into damasceninic acid by warming with dilute hydrochloric acid. ... 

Potassium Leiuene sulphonate, 177 Potassium ethyl sulphate, 50 Potassium methyl sulphate, 50 Preparations, general remarks, 47 Pressure tube, glass, 24, 78 furnace, 24 metal, 227... 

Methyl sulphate, see Dimethyl sulphate Methyl sulphide, see Dimethyl sulphide ... 

Neostigmine methyl sulphate [51-60-5] M 334.4, m 142-145 . Crystd from EtOH. (Highly TOXIC]. 

Methylphenazinium methyl sulphate [299-11-6] M 306.3, m 155-157° (198°dec by rapid heating). It forms yellow prisms from EtOH. Solubility in H2O at 20° is 10%. In the presence of aqueous KI it forms a semiquinone which crystallises as blue leaflets from EtOH. [Wieland and Roseen B 48 1117 1913 Voriskova Coll Czech Chem Commun 12 607 1947 Billow B 57 1431 1924]. 

Dimethyl selenide, (CH3)2Se.—An intimate mixture of selenium and amorphous phosphorus (5 2) is heated, and the black mass powdered and heated in a retort with concentrated sodium hydroxide and potassium methyl sulphate. The mixture foams and a yellow liquid distils over. This is separated from the water and fractionated to remove dimethyl diselenide, which is present in small quantity. 

Dimethyl telluride, (CH3)2Te.—The method first used for isolating this substance consisted in treating a potassium-tellurium alloy with a concentrated aqueous solution of barium methyl sulphate.1 It appears doubtful whether the method can actually be used for obtaining dimethyl telluride itself, although it might be used for derivatives of this body. An excellent yield of dimethyl telluride is obtained according to the equation 2... 

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