title: Studies toward the synthesis of cinachyramine. An efficient route to 1,5-diazabicyclo[4.4.0]dec-5-enes.
abstract: Hydrogenation (3 atm) of readily available pyrido[1,2-a]pyrimidines10,14, and17over 5% Rh/Al2O3forms 1,5-diazabicyclo[4.4.0]dec-5-enes9,15, and18in > 95% yield, providing a general route to this little-studied class of compounds. All attempts to form the tetrahydro-1,2,4-triazine moiety of cinachyramine (1) by rearrangement of amidinium dimethylhydrazone8using the procedures developed by Kamatori to convert hydrazone3ato tetrahydro-1,2,4-triazine4awere unsuccessful.
authors.affiliation: Department of Chemistry MS 015, Brandeis University, Waltham MA 02454-9110, USA.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Barykina-Tassa
authors.affiliation: Department of Chemistry MS 015, Brandeis University, Waltham MA 02454-9110, USA.
authors.forename: Barry B
authors.initials: BB
authors.lastname: Snider
keywords: 1,5-diazabicyclo[4.4.0]dec-5-enes; 1,5-hydrogen shifts; hydrazones; hydrogenation; pyrido[1,2-a]pyridimines