Alloxan monohydrate

Submitted by A. V. Holmgren and Wilhelm Wenner.1 Checked by T. L. Cairns and R. W. Upson. 

This amount was found to give best yields. 

It is very important that the temperature does not rise above 50°. If the addition of barbituric acid is carried out too rapidly, the temperature rise cannot be checked satisfactorily and the yield may drop considerably. 

If entirely pure alloxan monohydrate is desired, this material is recrystallized according to the directions in an earlier volume of this series.2 

The methods for the preparation of alloxan have been reviewed earlier.2 3 The present method is essentially that of Wemier.4 

If the second mother liquor is evaporated to about half of its original volume, a small third crop of very impure crystals may be obtained. 

Acetoacetanilide has been prepared by the reaction of aniline with ethyl acetoacetate 2 3 and by the reaction of ketene dimer with aniline.4 

Submitted by John H. Speer and Thomas C. Dabovich. Checked by W. E. Bachmann and R. O. Edgerton. 

In order to obtain practically colorless alloxan monohydrate (Note 5), 25 g. of the yellow crystals is dissolved in 37 cc. of hot water, the solution is boiled with Norite, and the hot solution is filtered into a 500-cc. round-bottomed flask. About 15-20 cc. of water is removed by distillation under reduced pressure on a water bath. The colorless crystalline residue is dissolved in the minimal volume of hot water, the solution is cooled somewhat, and to it is added 250 cc. of glacial acetic acid. After the mixture has been kept cold (5-10°) for four to six hours, the alloxan monohydrate is filtered. The yield is 20-21 g. (80-84 per cent recovery) (Note 6) of practically colorless crystals which melt at about 254° (Note 7) with decomposition. 

The submitters report that a single attempt to use the aqueous-alcoholic solution of barbituric acid obtained in Org. Syn. 18, 8, before recrystallization of the product gave an excellent yield of an apparently isomeric product unsuited for the preparation of alloxan. 

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Alloxan monohydrate from Eastman Kodak Company is satisfactory. It is dried to constant weight over soda-lime and phosphorus pentoxide in the vacuum desiccator at room temperature. It should be colorless, and readily and completely soluble in 5 volumes of cold water. The sample employed assayed 99-100% alloxan monohydrate by Tipson and Cretcher s method.2... 

Alloxan monohydrate has been prepared by the oxidation of uric acid with chlorine,1,2 or potassium chlorate and hydrochloric acid 3 by the oxidation of alloxantin,4 xanthine,5 uramil4 and... 

Biltz et al method (Ref 2) in which alloxan monohydrate is heated (80—90°) with anhydr urea followed by bubbling dry HC1 gas thru the mixt. The reaction is then drowned in w, cooled, filtered and recrystd from boiling w. Yield is 61.9% of theory. Spirodihydantoin is the parent compd of Dinitrospirodihydantoin (see below)... 

Alkylphosphonyl dichlorides, 37, 84 Alloxan monohydrate, 33, 3 Alloxan monohydrate, 32, 6 Alloxantin dihydrate, 33, 3 Allylbenzene, 31, 85, 86 Allylbromide, 31, 86, 36, 61 a Allyl 0 bromoethyl ethyl ether, 36, 62... 

Photoaddition of nucleophiles to heterocycles is often observed.1 Irradiation of acridine and its quaternary salt in ethanol produced 9,9 -bisacridan (151) as the major product besides a little acridan and 9a-hydroxyethylacridan.207 The reaction mechanism is most likely a hydrogen abstraction from the alcohol by the excited molecule, followed by competitive radical combination to yield 151. Irradiation of an aqueous solution of alloxan monohydrate and its derivatives produces an alloxantin-type dimer (152 R = H, Me, Et) by combination (at the 5-position) of a radical intermediate.208... 

SYNS ALLOXAN MONOHYDRATE DMESOXALYU CARBAMIDE MONOHYDRATE 2,4,5,6(1H,3H)-PYRIMI-DINETETRONE HYDRATE 2,4,5,6-TETRAOXOHEXA-HYDROPYRIMIDINE HYDRATE... 

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