You, Shuli et al. published their patent in 2008 |CAS: 93476-46-1

On November 12, 2008, You, Shuli; Xia, Jibao published a patent.Computed Properties of 93476-46-1 The title of the patent was A process for preparing 3,3′-biindolizine compounds. And the patent contained the following:

The invention relates to a process for the preparation of 3,3′-biindolizine derivatives I, wherein R1 and R2 are independently H, (un)substituted alkyl, NH2, etc. For instance, the invention compound II was prepared by dimerization of 1-indolizinecarboxylic acid Me ester in the presence of Pd(OAc)2, Cu(OAc)2, and K2CO3. The experimental process involved the reaction of Ethyl indolizine-1-carboxylate(cas: 93476-46-1).Computed Properties of 93476-46-1

The Article related to biindolizine preparation dimerization, Heterocyclic Compounds (One Hetero Atom): Pyridines and other aspects.Computed Properties of 93476-46-1

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics