5 7C i 4
Vol. 74
NOTES
Experimental Apparatus and Procedure for Tritiation of Multiple Bonds. ---The tritiation apparatus employed is illustrated in Fig 1 The hydrogenation bottlc coiitaining catalyst and material t o be tritiated wa5 placed i n a inechaiiicd shaker. Thc entire system with stopcock E open \vas evacuated Ivith ii water aspirator through stopcock A and flushed several times with tank hydrogen through stopcock G. An atmosphere of "cold" hydrogen is left in the bottlc by closing stopcock B . \\'ith the system evacuatcd a t 15-20 niin. pressure, stopcocks C antl F closed, and the mercury a t the top of the 35IJ-inl. buret :it stopcock D, the tritium anipoule is opencd a t the l m a k seal. The mercury i n the buret is pulled down with the Tocpler pump a t the base of the buret i n order to tr'iiisfer thc tritium from the ampoule into thc burct. Stopcock D is then closed :mtl the pressure in the anipoulc brought to 1 a t i n . with tank hydrogen. The gas i t i the ampoule \vxs then pulled into the Ixxet mid Toeplered back and forth bet\veeii buret ai1t1 ampoulc twice to ensurc thorough mixing. This process w;is rcpeatctl until til)out 1,50 nil. of gai :it 1 . i t i n . prcssurc IV:IS contained iii thc liuret. Thc shakcr \viis then started, antl after this quantity of gas \vas usrd i r i tlic rctluction, stopcock B was closed x i i t l the above proceclure rcpcateil. In all, this method of rcmoval of tritium antl rctltictioti with portions of 150 nil. of gas was curried o u t five tirncs. The buret ~ v ; i sthcn fillctl cornpletely ivith tiink hydrogen antl thc reduction allowed to go to cotnplctioii. T h e app:irntus should be erriploycd in mi effcient hood and sincc oncc used for tritiotion it b c c o ~ ~ i contarninatetl: cs thcrcafter, it should hc tiictl for triti;ttion expcrinicnts only.
Fig. 1 . -Tritiatioii a p p m t t u i Methylphenylcarbinol. --I i i :L Parr hydrogenatiori Iiottlc \yere placed 5.0 nil. of tlistillecl ncctoghetionc (11.1). 44--45', 1 mrri.) and 0.30 g . of platinum oxide catalyst. The reduction was carried out by the procedure described above employing a tritium ampoule containing 50 mc. (Oak Ridge value). The hydrogenation stopped by itself after 1158 ml. of Tas was absorbed in 3.5 hr. (Theoretical uptake of hytirogen for reduction of acetophenone t o carbinol was 1102 iiil.). The organic material was dissolred in ether and filtered to remove the catalyst. After most of the ether had bccn distilled off a t atmospheric pressure, the h i t trxces were rcnioved i,t vucuo. I n :I comparable cold run incthylphenylcarbiiioi (b.1). Y8", l3.
