CARBONYL AND THIOCARBONYL COMPOUNDS: I <i>a</i>. REACTION OF 9-DIAZOXANTHENE WITH <i>o</i>-QUINONES <i>b</i>. THE DIRECT PREPARATION OF HALOGENATED CYCLIC ETHERS FROM CERTAIN THIONES AND THEIR MOLLUSCICIDAL ACTIVITY

Abstract

The preparation and properties of 9-diazoxanthene are described. It reacts with tetrachloro-and tetrabromo-o-benzoquinone, 4-triphenylmethyl-1,2-benzoquinone, and phenanthraquinone to give the cyclic ethers IIIa, IIIb, IV, and V respectively. The action of hydrochloric acid – dioxane solution on the products is stressed.Tetrachloro- and tetrabromo-o-benzoquinone react with xanthione forming the halogenated cyclic ethers IIIa and IIIb respectively. A 1,2-benzopyran derivative IX is obtained by the action of tetrachloro-o-quinone on coumarin-2-thione. IX is toxic to Biomphalariaboissi snails in high dilution.