Ethoxyacetylene I reacts with tertiary aliphatic amines and water to yield (a-ethoxyvinyl) -trialkylammonium hydroxides 11. Several crystalline salts of these bases were obtained. Catalytic hydrogenation of (a-ethoxyvinyl) -trimethylammonium iodide IIa yielded trimethylammonium iodide and diethyl ether.Reppel) found that by the reaction of acetylene with trimethylamine and water vinyl-trimethylammonium hydroxide was formed.W e observed that an analogous reaction can be performed with ethoxyacetylene. When this compound was shaken with a solution of trimethylamine in water, heat was evolved, and after some time a strongly alkaline solution resulted. W e could obtain several stable and crystalline salts from the base. The iodide, picrate, and perchlorate were not hygroscopic, whereas the chloride, bromide, and sulphate were deliquescent.The analysis of the salts indicated that the base had the com-

Ethoxyacetylene I reacts readily with a mixture of aqueous solutions of formaldehyde and non‐aromatic amines yielding ethyl esters of derivatives of β‐aminopropionic acid III instead of “Mannich bases” II. Attempts to prepare the true Mannich bases under anhydrous conditions failed.