Methylisourea hydrochloride

Methylisourea hydrochloride decomposes on heating with evolution of methyl chloride. The decomposition temperature depends on the rate of heating, but reproducible values are obtainable if the rate of heating is controlled. Samples of pure (98-99%) (Note 12) methylisourea hydrochloride, introduced... 

The purity of the crystallized product, determined volu-metrically by Volhard s method, exceeds 98%. In this procedure, 10 ml. of a 1% solution of methylisourea hydrochloride is acidified with a few drops of nitric acid and treated with 20 ml. of 0.1 N silver nitrate. After removal of the silver chloride by filtration, the excess of the silver nitrate is estimated with 0.1 TV thiocyanate solution, using ferric alum as indicator. Alternatively, 10-ml. portions of 0.1 N silver nitrate, acidified with nitric acid, may be titrated directly with the 1% methylisourea hydrochloride solution in the presence of tartrazine. 

Methylisourea hydrochloride may be safely stored over long periods if kept in small, well-stoppered, filled bottles, which are in turn placed in a desiccator. 

Methylisourea hydrochloride has been prepared by the action of hydrogen chloride on a suspension of silver cyanamide 2 or a solution of cyanamide3-4 in methanol,3 and by the action of dimethyl sulfate on urea at 112°.6 The free base is obtained by treating the salt with powdered potassium hydroxide in a water-ether mixture 3 or with sodium methoxide in methanol.0... 

A. l-Phenyl-2-thio-4-methylisobiuret. Into a 500-ml. three-necked flask fitted with a Hershberg stirrer and reflux condenser are introduced a solution of 23.0 g. (0.35 mole) of 85% potassium hydroxide in 75 ml. of water, followed by 38.7 g. (0.35 mole) of methylisourea hydrochloride (Note 1). The clear liquid is diluted with ISO ml. of acetone, and the resulting suspension, containing finely divided crystalline solid, is treated with 27.0 g. (24 ml., 0.2 mole) of recently distilled phenyl isothiocyanate. 

Methylisourea hydrochloride is accessible from commercially available calcium cyanamide by the method described in Organic Syntheses ... 

Methyl iodide, 31, 33, 90 34, 61 38, 59 2-Methyl-l-iodopropane, 31, 32 2-Methyl-2-iodopropane, 31, 32 1-Methylisoquinoline, 38, 58 Methylisourea hydrochloride,... 

Cyanamide, NH2CN. Mol. wt, 42.04, m.p. 46°. Suppliers B, E, F. Preparation. - Under catalysis by hydrogen chloride, methanol adds to the triple bond of cyanamide with formation of methylisourea hydrochloride. In strongly alkaline solution... 

Addition of 95% ethyl acetimidate (94 g, 1.02 mol) to 2-methylisourea hydrochloride (37.8 g, 341 mmol) caused a moderately exothermic reaction the temperature spontaneously rose to the bp in 10 min. The mixture was held at a gentle reflux by cooling and, after the reaction had subsided, was allowed to cool unaided for 1.5 h. Crystalline acetimidamide hydrochloride (25 g, mp 165-170 °C) was separated by filtration and the filtrate was fractionally distilled. After a forerun of 2,4,6-trimethyl l,3,5-triazine [yield 12.3 g (10%)]. the title compound was obtained (— 80°C/ 3 Torr) yield 34.6 g (73%) mp 43.5 C. The distillation residue (8 g) was nearly pure acetimidamide hydrochloride. 

A soln. of Na-methoxide in methanol added dropwise during 15 min. to 2-phenoxy-4H-l,3-benzoxazin-4-one and 2-methylisourea hydrochloride dissolved in warm methanol, and refluxed 5 min. 2,4-dimethoxy-6-(2-hydroxyphenyl)-s-triazine. Y 93.6-99%. - This method furnishes asym. o-hydroxyphenyl-s-triazines difficult to obtain otherwise. F. e. and methods for the prepn. of o-hydroxyphenyl-s-trl-azines s. H. Brunetti and C. E. Liithi, Helv. 55, 1566 (1972). 

C2H6N4S2, N,N -Bis(thiocarbamoyl)hydrazine, 41B, 58 C2H7CIN2O, 0-Methylisourea hydrochloride, 35B, 34 C2H7N3O3, Biuret hydrate, 26, 570 39B, 33 C2H7N3O4, N-Methylurea nitrate, 21, 525 C2H7N5, Biguanide, 44B, 48... 

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