SYNTHESES OF RI LABELED ORGANIC COMPOUNDS BY IRRADIATION. THE NEUTRON IRRADIATION OF CHLOROBENZOIC ACIDS

>The recoil labeling method is applicable where conventional methods of incorporation of a radioactive isotope, such as synthesis or exchange, prove to be difficult or impossible. The recoil method holds promise in the labeling of complex natural products and in preparing large quantities of low-labeled material. There is some hope that some types of molecules with extremely high specific activity may also be prepared by recoil labeling. C-14 S-35, and Cl-36 are formed by the N-14 (n,p) C-14, Cl-35 (n,p) S-35, and Cl-35 (n, gamma ) Cl-36 reactions. S-35 atoms are produced at the JRR-1 pile through the reaction of thermal neutrons in the Cl-35 (n,p) S-35 process. alpha , BETA chloronaphthalene, o-, m-, p-chloronitrobenzene, and o-, m-, p-chlorobenzoic acids are irradiated in the JRR-1 pile at an approximate neutron flux of 10/sup 11/n/cm/sup 2//sec for 40 to 60 hours. After irradiation, one month was allowed for decay of short-lived activities arising from impurities in the irradiated compounds. o-, m-, p-dinitrodiphenyldisulfides are isolated from irradiated o-, m- , p-chloronitrobenzene by carrier technique. And o-, m-, p-dithiodibenzoic acids are isolated from irradiated o-, m-, p-chlorobenzoic acids and, mixture of benzoic acid and p-dichlorobenzene, by above method. The purification of these addedmore » carrier compounds is carried out by recrystallization and chromatography. These pure isolated carrier compounds are oxidized by the Schoniger method and their radioactivity measured as infinite thickness of barium sulfate. Radiochemical yields of o-, m-, p-compounds are tabulated. (JAIF)« less