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l,3-Dimethyl-5,6-diaminouracil was condensed with nitrous acid, thionyl chloride, glyoxal, oxalic acid, diacetyl and benzil, respectively. It was also treated with dilute hydrochloric acid whereupon l,l',3,3'-tetramethylhydurilic acid or 1,3,6,8tetramethyl-2,4,7,9-tetraketodecahydrodipyrimido[4,5-b,4',5'-e]pyrazine or a mixture of both compounds was obtained.During our synthesis of potential diuretics, we studied a number of reactions in which 1,3-dimethyl-5,6-diaminouracil (III), a key intermediate in the manufacture of theophylline, was condensed with nitrous acid, thionyl chloride, glyoxal, oxalic acid, diacetyl and benzil, respectively.In order to obtain the required diamine III, N,N'dimethylurea (I) and cyanoacetic acid were condensed in the presence of acetic anhydride to form N,N'-dimethyl-N-cyanoacetylurea which was converted by sodium hydroxide into l,3-dimethyl-6aminouracil; nitrous acid reacted with the uracil to form l,3-dimethyl-5-nitroso-6-aminouracil monohydrate (II). Since we used the continuous process described by Campbell and Campbell,3 only compound II was isolated; sodium hydrosulfite4 transformed II into III. Traube6 stated that the diamine III condensed with nitrous acid to form "l,3-dimethyl-4,5-aziminouracir'6 and assigned formula IV to this compound; neither the yield nor the melting point was reported, and the compound was characterized only by solubility data and a nitrogen analysis. When we repeated Traube's experiment, we obtained a product which, presumably, was identical with the product obtained by him. However, our analytical data did not correspond exactly to that calculated for formula IV.7 Acylation of IV with acetic anhydride and also with benzoyl chloride yielded the monoacyl derivatives (V). The complete analytical data obtained in the case of both acyl derivatives corresponded very closely to the calculated data. Although formula V indicates that these derivatives are 7-acyl compounds, the acyl group might be attached to the 8or 9-nitrogen atom.Interaction of the diamine III with thionyl chloride yielded a product to which we assigned formula VI.8 It was assumed that the diamine had reacted with thionyl chloride in the same manner as ophenylenediamine. In the latter instance, the structure of the heterocyclic produced, piazthiol, was established by physical chemical measure-(1) This paper represents part of a dissertation submitted by H. C. Godt, Jr., in partial fulfillment of the requirements for the Ph.D. degree in the University of Michigan.(2) Monsanto Chemical Company Fellow.(3) K. N. Campbell and B. K. Campbell, U. S.

During a study of the nitric acid oxidation of cyclohexanol (I) to adipic acid (V), 6-nitro-G-hydroxyiminohcxanoic acid i'll) and octahydro-5aII,10aH-4a,9a-epoxydibenzo-p-dioxin-5a,10u-diol (VIII) were isolated from reactions which were performed at temperatures from 10 to 20°. The structure proof of compounds II and VIII led to two new substances, 6amino-G-hydroxyiminohexanoic acid (III) and 6-oxocyclohexcn-l-yl benzoate (XI), as well as new routes for preparing the known substances 1,2-cyelohexanedione (X), its phenylosazone IX, and adipamic acid (IV). In view of the results obtained from acid hydrolysis and nitric acid oxidation of compounds II and VIII, a mechanism might be postulated for the nitric acid oxidation of cyclohexanol to adipic acid and the chief side products, glutaric and succinic acid, at temperatures above 35°b y assuming the theoretical intermediate formation of compound II, compound VIII and/or compound X. No evidence, however, was found for the presence of the latter three particular compounds when operating at tempcratuies above .35°which are normally employed in this oxidation reaction.

The reaction of boric acid with amines has been found to yield either N-substituted ammonium triborates or N-substituted ammonium pentaborates. The major factors governing which product is formed are the steric requirements of the amine and the mole ratio of the reactants. Evidence is presented for the proposed structure of these products.

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