Vol. 71 g., m. p. 190-213°, was recrystallized three times from dioxane yielding a product that melts at 248.5°. Substituted 2-N4-Acetylsulfanilamidoquinoxalines The amines were dissolved or suspended in pyridine and ^-acetylaminobenzenesulfonyl chloride added while the mixture was stirred, 2 -N4-Acetylsulfanilamido -5 (or 8)-chloroqulnoxaline.-To a mixture of 11.7 g. of the amine in 60 ml. of dry pyridine was added 16.7 g. of ^-acetylaminobenzene sulfonyl chloride in four portions at ten-minute intervals, During the addition, the mixture warmed up to 35°. After being stirred for one hour, the resultant clear yellow solution was heated on a water-bath at 650 for one-half hour. The mixture was then poured into 800 ml. of hot water and the product, which crystallized when the mixture was stirred, was filtered and air dried. The crude product, 20.0 g., was dissolved in 250 ml. of 1.3 N sodium hydroxide and filtered; 4.45 g. of insoluble material, m. p. 208-210°, was obtained. The filtrate was acidified with glacial acetic acid yielding light yellow amorphous material, m. p. 245-252°( 14.7 g., 62% yield). The analytical sample was crystallized from glacial acetic acid, m. p. 252-255°.2-N4-Acetylsulfanilamido-6(or 7) -carboxamidoquinoxaline.-A mixture of 1.08 g. of 2-chloro-6(or 7)-carbamidoquinoxaline, 1.07 g. of acetylsulfanilamide, 0.65 g. of potassium carbonate and 50 mg. of copper powder in a Pyrex test-tube was stirred and heated at 180-190°in an oil-bath for fifteen minutes. The dark mixture was extracted with 10 cc. of 10% sodium hydroxide, filtered from the chi oro compound that had not reacted and precipitated by acidification with dilute acetic acid. The oil that separated solidified on trituration with isopropyl alcohol. Recrystallization from glacial acetic acid yielded product, m. p. 277°about 500 mg. SulfonamidesThe acetyl derivatives were hydrolyzed by boiling with aqueous sodium hydroxide or ethanolic hydrogen chloride. 2-Sulfanilamido-5(or 8)-chloroqumoxaline.-A solution of 11.95 g. of the acetyl compound in 75 ml. of 2.5 Nsodium hydroxide was heated for one-half hour on a steam-bath. The crude product, 10.25 g., 97% yield, was precipitated by neutralization with acetic acid. The crude product, m. p. 210-213°, was purified in 87% recovery by dissolving in hot 5 N ammonium hydroxide, treating with charcoal and precipitating with acetic acid, m. p. 213-215°.
NotesVol. 70 correct to compare heat of adsorption data with adsorption data plotted according to equation 8 of Walker and Zettlemoyer.4 Beebe, et of.,8 indicated the Anderson monolayer volume at a smaller value than the B. E. T. monolayer, thus making Anderson's modification appear to be in the wrong direction. It is true that for a given amount adsorbed, the numerical value of V/ Fm from Anderson's equation will be smaller than from the B. E. T. equation, but for this very reason, if the point where Anderson's F/Fm is unity is marked off on a scale graduated in terms of B. E. T.'s F/Fm, it must fall at a place where the graduation shows B. E. T.'s F/Fm to be greater than unity.These facts support Anderson's equation 6. However, in deriving his equation 17,2 he has used an expression (equations 13 and 15) for the volume adsorbed in the nth. layer, F", which holds only for the simple B. E. T.5 model. The appropriate expression for Anderson's model instead of his equation 15, is given by _ Vmcja~lxD " 1 + (ej)x This, when summed for values of n from 1 to », gives an isotherm equation which is identical with the one obtained by a more direct method in a later publication,6 as it must since the two equations are deduced from identical postulates.
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