2770 NOTES Vol. 75 In an attempt to increase the efficiency of the re-generation process an experiment was carried out at 60' since it was believed that slow rates of equili-bration might be in part responsible for the trailing edge in the sulfuric acid elution. Operation a t higher temperature not only does not improve the regeneration but actually the removal of HsS04 takes more water (cu. 32 column volumes) than a t lower temperature indicating that the tailing in the elution band is not due to slow rates of equilibra-tion. I t probably arises from a pronounced non-linearity of the adsorption isotherm. It is inter-esting to note that the copper band at 60' definitely showed some adsorption, the apparent elution con-stant E 4 being cu. 1 instead of the theoretical maxi-mum ca. 2.5 when no adsorption takes place. At the lower temperature the copper band was less strongly adsorbed, but did not travel with elution constant as large as 2.5. (4) E has been defined (K. A. Kraus and G. E. Moore, THIS Joua-NAL, 73, 9 (1951). as the distance (cm.) a band moves under equi-librium conditions, per cc. of eluent io a 1-cm.2 column. This note describes the preparation of several 23-disubstituted benzoxazoles, in the hope that they may be of therapeutic value. X (5 position): C1, HOZC-, or Bu02C-Y (2 position): SH, OH, NHz, or NHz-C-NH-II "QJY NH Experimental 2-Benzeneazo-Cchlorophenol.-A modification of the method of Krause' was found to prevent the formation of tar. A solution of benzenediazonium chloride made from 0.1 mole (9.3 g.) of aniline was added a t -3 to 0' with stirring over a period of two hours to a cold solution of 0.1 mole (12.9 9.) of p-chlorophenol, 4.0 g. of sodium hydroxide and 2.9 g. of sodium carbonate crystals in 100 ml. of 90% ethanol and 200 ml. of water. The stirring was maintained until there was no color reaction with alkaline 8-naphthol, the solution then acidified with acetic acid, filtered, and the solid product (23 g. of orange yellow needles melting at 105-107') washed with water. Recrystallization from 60% acetjc acid gave orange prismatic needles melting at 110-111 .
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