The action of alkali on a number of coumarins with methyl groups in the 4-position has been studied in detail. Each of them yields readily only one acid which, though fairly stable, has the property of undergoing change into the corresponding coumarin under the action of heat and dehydrating agents. The acids, however, cannot be converted into stabler isomers by methods which are definitely effective in convertingcis intotrans acids. The methyl ethers of the acids are easily obtained by methylating the acids or the original pyrones in the presence of alkali in an aqueous alcoholic medium. Their properties are those of ethers of thetrans acids since they cannot be converted into isomeric compounds by methods which are definitely successful in convertingcis intotrans ethers. It is therefore concluded that the acids and their ethers derived from 4-methylcoumarins aretrans compounds. The comparatively ready formation of these acids and their ready conversion again into the coumarins are explained on the basis of the tautomeric mechanism which renders the geometrical inversion very facile.

Various methods of extracting gossypol from cotton-seed meal have been examined: (1) removal of the oil with petroleum ether and then extraction of gossypol with ether, (2) same as (1) but moistening the seed meal before ether extraction, (3) precipitation of gossypol as the acetic acid compound, (4) precipitation of gossypol as the aniline compound and (5) use of other solvents particularly chloroform not so far investigated. It has been confirmed that moistening of the meal is necessary for complete extraction with ether and when this is done only aniline works satisfactorily as the precipitant. The preliminary removal of the oil is not absolutely essential though desirable. With chloroform as the solvent, neither removal of the oil nor addition of moisture is necessary. Hence the use of chloroform as the solvent and aniline as the precipitant is most satisfactory. For recovering gossypol from the anilino compound decomposition using potash and sulphuric acid are not satisfactory. A new method has been evolved using acetic anhyride. Pure gossypol thus obtained melts at 189° and the solvent employed makes no difference. It gives no methoxyl values. A few other properties are described.

With excess of aniline, gossypol forms tetraanilino-gossypol which decomposes on heating for a long time at 110° or for a short period at 180°, the products being aniline and dianilinogossypol. The two anilino compounds resemble closely except for the fact that the tetraanilino-compound contains more nitrogen and evolves aniline long before its final decomposition point is reached. Acetylation and methylation yield only gossypol derivatives, aniline being removed; acetyl and methyl derivatives of the anilino compounds could not be obtained.

The methods adopted by Adamset al. for the methylation of gossypol do not seem to produce a uniform product of the hexamethyl ether having constant properties. The following methods have now been employed: (1) methylation of hexaacetate using dimethyl sulphate and alkali in acetone medium, (2) methylation of gossypol with diazomethane in methyl alcoholic solution, (3) with methyl iodide and potassium carbonate in acetone solution and (4) with dimethyl sulphate and alkali. All the products had the same melting point, 130°, and gave analytical results corresponding to the hexamethyl ether. The methods which do not employ caustic alkali give samples which are less coloured. The methyl ether is unaffected by treatment with hot dilute sulphuric acid and hence does not seem to have the formula corresponding to the structure of glycosides.

The white acetate of gossypol is conveniently prepared by employing acetyl chloride and pyridine in the cold for the acetylation. The use of acetic anhydride and a catalyst at elevated temperatures produces a high melting pyrone derivative.