SYNTHESIS OF A PROTONATED C-2-SYMMETRICAL N,N-CHIRAL PROTON SPONGE

The hydrogen iodide salt of 1,8-bis-(N-benzyl-N-methylamino)naphthalen e was synthesised as an 89/11 ratio of diastereomers in good yield. Th e structure of the major (+)-(RNRN/SNSN) diastereomer was determined b y single crystal X-ray diffraction. The minor diastereomer is shown to be the meso-(RNSN) form by performing H-1 NMR n.O.e studies on isotop ically desymmetrized N-[C-13]-methylamino)-8-(N'-benzyl-N'-methylamino ) naphthalene (HI salt). The half-life of interconversion of meso and dl forms is less than 2 minutes in CD2Cl2, at ambient temperature. (C) 1998 Elsevier Science Ltd. All rights reserved.