10.1071/CH9781769
The research focuses on the synthesis of various polycyclic quinazoline compounds, which are structural analogues of tetrodotoxin, a potent neurotoxin found in certain marine animals. The key intermediate used in the synthesis is 2-oxoadamantane-1-carboxamide (12), which is prepared from adamantan-2-one (7) through a series of reactions involving diazomethane, selenium dioxide, and thionyl chloride. The resulting intermediate (12) is then subjected to reductive amination to produce 2-amino-adamantane-1-carboxamide (14), which can be further transformed into various target compounds such as 3,5-diazatetracyclo[7,3,1,17~11,01~6]tetradecane-4-iminium sulfate (3), 3,5-diazatetracyclo[7,3,1,17~11,01~6]tetradecan-4-one (4), and 3,5-diazatetracyclo[7,3,1,17~11,01~6]tetradecane (5) dipicrate. Other related compounds like 3-oxa-4-azatetracyclo[6,3,1,16~10,O115]tridec-4-en-2-one (15) and 3,4-diazatetracyclo[6,3,1,16~10,O115]tridec-4-en-2-one (16) are also synthesized. The study aims to explore the stability and potential biological activities of these compounds, which are expected to be more stable than the toxin due to their cage-like structure.