THE SYNTHESIS OF ETHANOLAMINE-1-C¹⁴

Abstract

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.

Phospholipids chiral at phosphorus. Dramatic effects of phosphorous chirality on the deuterium NMR properties of the choline head group of phospholipids in the liquid crystalline phase

“…The synthesis involves three major steps: (a) synthesis of specifically deuterated choline; (b) synthesis of DPPsC; (c) separation of DPPsC into Rp and Sp isomers. The specifically deuterated cholines were obtained as follows: [2,2-D2]choline iodide (precursor of [a-D2] DPPsC) from A,/V-dimethylglycine ethyl ester according to Dauben and Gee (1952), [l,l-D2]choline iodide (precursor of [/3-D2] DPPsC) from cyanoethyl benzoate according to Douglas and Burditt (1955), and [(CD3)3]choline chloride from MSD Isotopes (99 atom % enrichment). These choline halides were converted to their respective tosylate salts by using silver tosylate.…”