It has been proved that the rnethylsulfonyl group can exert a (negative) mesomeric effect.In view of the fact that the present-day literature contains many discussions with respect to the problem whether the methylsulfonyl group has a (negative) mesomeric effect, it may be useful to publish, in a very provisional form, some results obtained in our laboratory during recent years.Our method OE attack consisted in the determination OC the reaction rate constants for the deacylation of acetylaminobenrene and certain of its derivatives in methyl alcoholic sodium methoxide I ) .
HNAc
O n boiling aromatic ortho-cyano-acylamino compounds in alkaline alcoholic or phenolic solution -medium ROH -4-RO-substituted quinalzolines are formed. Some examples of this reaction are described.Verkade, Wepster, et al. have published extensive studies on the rate of the catalytic deacetylation of aromatic nitro-acetylamino compounds in alkaline medium 1). Similar studies have also been made with regard to related compounds which, instead of the nitro group, contain another substituent with a -M and/or a -I effect, in order thus to arrive at a (semi-)quantitative comparison of the magnitude of these effects of the substituents in question. Apart from two preliminary communications 2 ) . this work is as yet unpublished. During this work ortho-cyano-acetylaminobenzene was found to behave quite differently from the corresponding meta and para compounlds. W h e n the first-mentioned compound was boiled with a solution of sodium methoxide in )absolute methyl alcohol, only a small portion of the substance was deacetylated in the normal way, i.e. converted into ortho-cyano-aminobenzene; the main product of the reaction was a compound C,,H,,N20 with quite different proporties. This finding formed the starting point for the work to be described below.W e soon began to suspect that the product in question was 4-methoxy-2-mtrthylquinazoline I, which must then have been formed 1) A survey of this work was given by P. E. Verkade
Im vorliegenden Beitrag wurde der Einfluß des Erweichungsprozesses auf die Reduktionsgeschwindigkeit von Sinter untersucht. Dabei wurde die Reduktionsgeschwindigkeit von Hochofensinter in einem Temperaturbereich um den Erweichungspunkt bestimmt. Es wurde ein rapider, mit dem Erweichungseffekt wie auch mit dem Porositätsschwund verknüpfter Geschwindigkeitsrückgang festgestellt. Diese Erscheinung findet in einem Temperaturbereich statt, der den Temperaturen des Erweichungsbeginns beim untersuchten Sintermaterial im vorreduzierten Zustand entspricht. Somit ist der Erweichungsvorgang als grundlegende Ursache für die festgestellte Abnahme der Reduktionsgeschwindigkeit zu betrachten. Mikroskopische Direktbeobachtungen der Reduktion von Sinter im Erweichungszustand zeigten Erscheinungen, die zu einem Porositätsschwund führen. Messungen des Porenvolumens und der spezifischen Porenoberfläche an Sinter – vor wie nach abgeschlossener Erweichung und Reduktion – bestätigten die Porositätsabnahme. Diese erschwert den Reduktionsgaszufluß zu den Eisenoxiden und verlangsamt so die Reduktionsgeschwindigkeit.
This paper contains data on the (pseudo)catalytic deacylation of 1-and 2-acetylaminonaphthalene, five homonuclear acetylamino-rnononitmnaphthalenes (including the 2,3-isomer), five heteronudear acetylaminomononitronaphthalenes. and some other acetylarninonaphthalene derivatives in an alkaline medium. T h e rates of deacylation are discussed in some detail, mainly on the basis of the peculiar electronic properties of the naphthalene nucleus, and from the point of view of the theory of steric effects on mesomerisrn.Introduction. In previous papers of this series 1 ) a detailed discussion was given of the mechanism of the (pseud0)catalytic deacylation of acylaminonitrobenzenes in an alkaline medium and of the use of this reaction for studying steric effects on mesomerism. In the present paper we shall discuss the results of similar deacylation experiments with suitable naphthalene derivatives. Here again emphasis will be laid on steric
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