In a
3-l. round-bottomed flask are placed
500 cc. (400 g., 8.7 moles) of absolute alcohol which has been saturated in the cold with
hydrochloric acid gas (Note
1),
870 cc. (680 g., 14.8 moles) of 96 per cent alcohol (Note
2), and
70 g. (1.03 moles) of methyleneaminoacetonitrile (Note
3). This mixture is refluxed on a
steam bath for three hours (Note
4). During the refluxing,
ammonium chloride separates. After the reaction is complete, the hot alcohol solution is filtered with suction and the filtrate cooled, thus allowing the
glycine ester hydrochloride to separate in fine white needles. The product is filtered with suction, sucked as dry as possible on the filter, and then allowed to dry in the air. The yield is about
110 g. The alcohol from the filtrate is distilled (Note
5) until about one-third of its volume is left; it is cooled again, when a second crop of crystals is obtained. The total yield of product, m.p.
142–143°, varies from
125 to 129 g. (
87–90 per cent of the theoretical amount). If a very pure product is desired, the material may be re-crystallized from
absolute alcohol.