Pilgeram et al. (4) have reported a synthesis of uniformly labelled ethanolamine-C14 from barium carbonate-C14 via acetylene and ethylene oxide, yielding di-and tri-ethanolamine as by-products.We have synthesized ethanolamine-1-C1"rom radiocyanide through the formation of (C1"-cyano)methyl benzoate (1, 3) and its subsequent reduction with lithium aluminum hydride t o ethanolamine in 30y0 over-all yield. This method involves only two stages and yields solely primary anline. T h e reactions are as follows: cyanide-C14 (3.28 X lo7 counts/min. total activity) in 0.5 ml. of water cooled I in an ice-bath and stirred with a magnetic stirrer was added 0.24 ml. of 37% I forinalin (2.7 mlM. of formaldehyde). After one hour, 0.30 ml. (2.6 mM.) of benzoyl chloride was added, and stirring a t O°C. continued three hours longer. After the addition of 3 ml. of 5% sodium bicarbonate, the reaction misture was extracted continuously with ether for two to three hours. T h e ether extract was dried thoroughly, first over calcium chloride, then over Drierite.T h e cyanomethyl benzoate was reduced without isolation by the gradual addition of the dried ether solution to 3.5 ml. of an ethereal solution of lithium aluminum hydride (approximately 2.6 mM. per ml.). T h e complex was decomposed by stirring with 30 ml. of water, added slowly, the ether was removed by evaporation, and the aqueous phase was saturated with carbon dioxide. T h e aluminum hydroxide was centrifuged off and washed thoroughly with several portions of hot water. T h e supernatant and washings were combined, 1 ml. of ethylene glycol monobutyl ether (2) and 5 ml. of 0.5 N sodium hydroxide added, and the ethanolamine and water removed by lyophilization and condensed into a trap cooled with dry ice -isopropyl alcohol. T h e residue remaining was talten up in water, 1 ml. of ethylene glycol monobutyl ether added, and lyophilization repeated. This process was carried out four times altogether. For personal use only.

Cyanogen bro~nide reacts n i t h the sodium salts of lower aliphatic acids a t 250-300' C to form an a-keto isocyanate as the primary product. The latter ~~ndergoes subsequent pyrolytic decomposition to a nitrile and carbon dioxide. A mechanism is proposed to account for the observed interchange of labelled carbon atoms between the CN group of the cyanogen bromide and the carboxyl group of the salt in the over-all reaction.

Syntheses on a semimicro scale of thioethyl acetic, w-thiocthyl propionic, and w-thioethyl hutyric acids labellecl \\lit11 carho~i-14 in tlie carbox)rl group arc: tlcscribed. The conipouncls \\.ere chromatograplied on filter paper \\,it11 butanol-\\.atel--arii~iionia as the de\,eloping sol\.ent, ancl tlie R p \'al~~es cletel-minctl.