Preparation of N-arylmethyl aziridine derivatives, 1,4,7,10-tetraazacyclododecane derivatives obtained therefrom and N-arylmethyl-ethanol-amine sulphonate esters as intermediates

摘要

PCT No. PCT/GB96/00552 Sec. 371 Date Dec. 2, 1997 Sec. 102(e) Date Dec. 2, 1997 PCT Filed Mar. 8, 1996 PCT Pub. No. WO96/28420 PCT Pub. Date Sep. 19, 1996Aziridines may be subjected to a cyclooligomerization reaction to produce polyazacycloalkane compounds useful for example in the preparation of chelating agents for use in diagnostic imaging contrast agents. N-benzyl-aziridine in particular is useful as it can be cyclotetramerized and debenzylated to yield cyclen, a key intermediate in chelating agent preparation. The invention provides a particularly attractive route to production of N-benzyl and other N-arylmethyl aziridines of formula (I) where each R1 is independently hydrogen or a group AR and Ar is an optionally substituted phenyl group. The process comprises reacting a purified N-arylmethylethanolaminesulphonate ester with a base. N-arylmethyl-ethanolamine sulphonate ester of the formula R'NHCH2CH2OSO3H, wherein the N-arylmethyl group R' is an N-(bisarylmethyl) or N-(triarylmethyl) group, as intermediates. In a further aspect, the invention provides compounds of formula (II) where Ar and R1 are as hereinabove defined and at least two differing ArCHR21 moieties are present.