Adenine precursor synthesis I am currently exploring the synthesis of xRNA, which contains benzo-expanded purine and pyrimidines. I have found this paper which deals with exactly this subject, and provides the following synthetic pathway for the xA ribonucleotide.



Unfortunately, the first 5 synthetic steps are omitted from the paper, and are likely to be found in one of the following three papers, none of which are publicly available.

1. 2. 3. 

Nonetheless, I am interested in any synthetic pathway which will lead me from the first to the second molecule shown above. I understand the presented material, but as an undergraduate cell biologist, I am a little rusty on my synthetic organic chem.

EDIT: The first thing that came to mind was the condensation of a biscarbonyl electrophile and bisamine nucleophile like in pyrimidine synthesis.
Well, you are right, the synthesis of your second compound is described in DOI:10.1021/ja038384r: