Extraction process: Schwyzer, Die Fabrikation Pharmazeutischer und Chemisch-Technischer Produkte (Berlin, 1931).
Hope you can read German.
Theobromine is great stuff. Since you know little about it, first do a google search. Then do a google search for caffiene. You can also look these up on www.chemfinder.com
Make sure that you note the similarities--they occur together naturally in at least some abundance and therefore you will have a difficult time separating the two. Aside from that, you should look in the Merck Index, available at your local library. There is also a book called 'The Chemistry of Chocolate' put out not too long ago.
3,7-dihydro-3,7-dimethyl-1H-purine-2,6-dione. Also 3,7-dimethylxanthine.
The principal alkaloid of the cacao bean wihich contains 1.5-3% of the vase. Also present in cola nuts and in tea. Usually extracted from the hull of cacao beans which contain 0.7-1.2%.
Synthesis is from 1898.
mp 357 deg C, subl. 290-295 deg C.