Homologous disodium pyrazolonedicarboxylates (8, 16f and 16g) as possi
ble protectors of cis-DDP induced nephrotoxicity, have been prepared b
y the reaction of hydrazine with di-t-butyl ethyl beta-keto triesters
(5b, 13b and 13c) and subsequent hydrolysis of formed di-t-butyl pyraz
olonedicarboxylates (6b, 14b and 14c).