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synopsisHigh molecular weight polyspiroimides have been prepared by reacting diamines with the dianhydride of carboxymethanetetraacetic acid in polar organic solvents. Alternatively, thermal condensation of the preformed salt made from equimolar amounts of diamine and methanetetraacetic acid (MTA) can be used. These all-aliphatic polyimides are soluble in certain organic solvents, and possess good thermal-oxidative stability.

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From the residue the 2,4-dinitrophenylhydrazone (m.p. 238-239°) of benzophenone was prepared. From the aqueous alkali ro-toluic acid (m.p. 111-112°) was precipitated.Oxidation of triarylethylene glycols with selenium dioxide.The following technique yielded a crystalline benzoin (II)from triphenylethylene glycol and from 1,1-dipheny l-2-otolylethylene glycol, but not from any of the other glycols in Table I. A molten mixture of 5 g. of 1,l-diphenyl-2-otolylethylene glycol and 1.5 g. of selenium dioxide was stirred and maintained at a temperature of 200°for 5 min. The cooled mixture was triturated with ether which was in turn washed with aqueous sodium bicarbonate, dried, and evaporated. The residue was recrystallized twice from hexanebenzene to give 3.2 g. (65%) of a-phenyl-2-methylbenzoin, m.p. 116-117°with or without admixture of authentic material.1 a-Phenylbenzoin from benzoyl cyanide. To the Grignard reagent prepared from 94 g. of bromobenzene and 1.5 g. of magnesium in 75 ml. of ether there was added dropwise over a period of 30 min. a solution of 2.6 g. of benzoyl cyanide14 in 40 ml. of ether. A granular precipitate appeared in the stirred reaction mixture as rapidly as the cyanide was added. The reaction mixture was poured into a vigorously (14) T. S. Oakwood and C. A. Weisgerber, Org. Syntheses,

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Inden (I) kondensiert mit Alkoholen (II) in Gegenwart ihrer Alkoholate zu den 1,3‐Dialkyl‐indenen (III).