In the previous papers we have reported that some tertiary amine derivatives of 1, 2-dithiolane possess protective activity against the lethal effects of ionizing radiation in mice. In the present work, we have continued to prepare some bismercaptoamino-alkanes 7, 8 and, 9, and a dimercaptohy drazide 10, which show structural analogy to MEA and APT or 4, and hold promise as radioprotective drugs.These compounds were prepared as follows:The ethyl ester 14 of β,β,-dibenzylmeroaptoisobutyric acid (16) reacted with hydrazine to give the corresponding hydrazide 16; 16 via sodium azide reaction was converted to 1, 3-dibenzylmercapto-2-aminopropane hydrochloride (17).a, y-Dibenzylmercapto-l-aminobutane (12) was prepared similarly from a,y-dibrom-obutyryl bromide (11).The debonzylation of 12, 15, 17 and 20 was done with metallic sodium-liquid ammonia and the products were preoipitated as mercuric salts, which in turn were treated with hydrogen sulfide in alcohol to yield the pure thiols.Preliminary antiradiation test showed that all the compounds bearing bisthiol function exhibit protective activity in mice.9 has moderate protective effect against 1Htba1 radiation. Details of the pharmacological results will be published elsewhere.