Thu hydrochlorides listed in the footnotes to Table I were prepared by dissolving ! lie liases in dry ether and adding slowly with st ¡.ring an ether solution containing slightly more than two equivalents of hydrogen chloride. The salts were purified by recrystallization from an anhydrous alcohol ether mixture. They proved to be somewhat hygroscopic and consequently most of the compounds were submitted as the bases for pharmacological testing.N ,N -Bis-(2 -diethylaminoethyl) -anilines (II).-A suspension of I).8 mole of the primary aromatic amine, 0.7 mole (121) g.) of 2-dieihylaminovthyl chloride hydrochloride, 1 .2 moles ( 160 g.j of anhydrous potassium carbonate, 2 g. of copper bronze powder and 880 ml. of benzene was heated under reflux with stirring as described above for twenty-four hours. An additional 11.8 mole !Ó2 g.) of 2diethylaminoethyl chloride hydrochloride was then added and the stirring and heating were continued for ait additional twelve hours. The reaction mixture was then cooled, aqueous sodium hydroxide was added and the mixture was extracted with el iter as described in the preceding section. The ether extracts were dried, the ether was removed, and" the residue was fractionated. A forerun consisting largely of the N-(2-diethylaminoethyl) -aniline distilled first, followed by the higher boiling N,N-bis-(2diethylaminoethyl) -aniline.
The examination of synthetic rubbers prepared by the copolymerization of butadiene with various olefins has shown that the nature of the olefin exerts a considerable influence on the properties of the rubbers obtained. Relative to butadienestyrene rubbers the butadiene-dichlorostyrene rubbers are more easily milled and processed and show better hot tensile strength. The butadienevinylpyridine rubbers are outstanding in tensile strength but are nervy and tough and mill poorly.
The conversion obtainable in the vapor phase nitration of propane with nitrogen dioxide at practical contact times may be substantially increased by the addition of oxygen to the reaction mixture. The optimum conversion obobtainable at two minutes contact time with oxygen is appreciably higher than at contact times up to and including fourteen minutes without oxygen. The
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