Stereochemistry of Diphenyl

Abstract

THE stereochemistry of diphenyl, as was shown in the “Research Items” in NATURE for April 2, p. 512, in reference to a paper by Prof. R. Kuhn, continues to produce problems of great interest. At a meeting of the Chemical Society held on May 5, a new ‘dynamic’ effect of groups in the 2:2′ positions was described.¹ We have now effected the optical resolution of the monomethiodide of 2:2′-bisdimethylaminodiphenyl: NMe₂ NMe_aI The d- and l-methiodides have [α] ± 48° in aqueous solution, in which ionisation is complete, and cold solutions retain their activity for indefinite periods. In aqueous solution at 100°, half-racemisation occurs in just over two hours.