1,2-Bis(diazoacetyl)ethane 1,6-Bis(diazo)-2,5-hexanedione 19690-35-8 2,5-Hexanedione, 1,6-bis(diazo)- 23133-12-2 Diazan Diazane Diazane (VAN) Diazane (pharmaceutical) NSC 271276