Methylene aminoacetonitrile

In a 5-I. round-bottom flask, fitted with a mechanical stirrer and surrounded by an ice-salt bath, are placed 1500 cc. of technical formaldehyde (sp. gr. 1.078/20°) (Note 1) and 540 g. of ammonium chloride. A thermometer is placed in the liquid, which is cooled to o°. This temperature is maintained throughout the entire reaction (Note 2). Stirring is commenced (Note 3) and a solution of 490 g. of 98 per cent sodium cyanide in 850 cc. of water is dropped into the mixture of ammonium chloride and formaldehyde at such a rate (about 90 drops per minute) that at least six hours will be required for this addition. When one-half the sodium cyanide solution has been added, all of the ammonium chloride will be in solution. At this point, the addition of 380 cc. of glacial acetic acid is started at such a rate (2 to 2.5 cc. per minute) that the addition of both the acid and the remainder of the sodium cyanide solution will be completed at the same time. The methylene aminoacetonitrile begins to separate in white crystals shortly after the addition of the glacial acetic acid has commenced. After all the sodium cyanide solution and acetic acid have been added, the mixture is stirred for an hour and a half longer then the precipitate 

The formalin contains 35 per cent formaldehyde by weight, as determined by specific gravity. It should contain no suspended paraformaldehyde. 

During the reaction, the temperature should be kept as near o° as possible and should never rise above 50. If the temperature goes higher, a heavy oil is sometimes obtained instead of the crystalline product. It is not difficult to maintain the low temperature when the formaldehyde and ammonium chloride are cooled to o° before any of the sodium cyanide is added. 

In order to obtain good yields, the stirring must be vigorous throughout the entire reaction. 

With careful washing, 500 cc. of cold water should be sufficient to remove all chlorides. 

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Methyl chloroacetate, 7,17 Methyl cyanoacetate, 3, 56 Methylene Aminoacetonitrile, 4, 31,47... 

In a 5-I. flask fitted with a downward condenser, are placed 340 g. of methylene aminoacetonitrile (p. 47) and 2500 g. of 48 per cent hydrobromic acid (Note 1). The mixture is heated on the steam bath for three hours (Note 2). The pressure in the apparatus is then reduced and dilute acid and formaldehyde are distilled into a water-cooled receiver until the separation of ammonium bromide from the reaction mixture causes bumping. This occurs when approximately half of the liquid has been distilled over. The ammonium bromide is filtered from the hot liquid and washed with a small amount of cold water the filtrates are returned to the flask and distillation continued as nearly as possible to dryness (Note 3). The residue is dissolved in 2 1. of cold methyl alcohol and filtered to the filtrate is added 350 cc. of pyridine, with vigorous shaking (Note 4). 

Methylene aminoacetonitrile has been prepared by the action of formaldehyde on aminoacetonitrile,1 and by the action of formaldehyde on a mixture of ammonium chloride, potassium cyanide, and acetic acid.2... 

When one-half the sodium cyanide solution has been added, all of the ammonium chloride will be in solution. At this point, the addition of 380 cc. of glacial acetic acid is started at such a rate (2 to 2.5 cc. per minute) that the addition of both the acid and the remainder of the sodium cyanide solution will be completed at the, same time. The methylene aminoacetonitrile begins to separate in white crystals shortly after the addition of the glacial acetic acid has commenced. After all the sodium cyanide solution and acetic acid have been added, the mixture is stirred for an hour and a half longer then the precipitate... 

Methyl anthroquinone, IV, 43-44 Methyl benzoate, III, 71, 72 Methyl bromide, III, 29 Methylene aminoacetonitrile, IV, 31, 47-48... 

Other reactions with nitrogen compounds. For the preparation of methylene-aminoacetonitrile (m.p. 129°) a mixture of formalin (18.9 moles) and ammonium chloride is stirred at 0° during the addition in 6 hrs. of an aqueous solution of sodium cyanide. ... 

Microwave studies on aminoacetonitrile and some deuteriated analogues indicate that the amino-group is trans to the methylene (62). 

Aminoacetonitrile reacts with formaldeh de under alkaline conditions in the same manner as other piiman- amines, ghing trimeric methylene-aminoaoetonitrile ... 

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