Chemical behavior of dicyanocob(III)yrinic acid heptamethyl ester and cob(I)yrinic acid heptamethyl ester in some preparative experiments.

Preparations of C10 acetate, trifluoroacetate, and chloro derivatives of dicyanocobyrinic acid heptamethyl ester ('cobester') are described. The nature and properties of intermediates in the synthesis of the 10-chloro derivative are discussed, and the electronic absorption spectra of the products are presented.