C 2829a (OTTO) Cyclopropane-1,1-dicarboxylic acid, 97% Cas 598-10-7 - used in the preparation of new heterocyclic derivatives of cyclopropane dicarboxylic acid containing thiadiazole and 1,2,4-triazole moieties. C 2829a (OTTO) Cyclopropane-1,1-dicarboxylic acid, 97% Cas 598-10-7 - used as the pharmaceutical intermediates.