Displacement reactions of 2,3-dichloro-6-nitroquinoxaline: synthesis of s-triazolo[3,4-a]quinoxaline

Abstract

2,3-Dichloro-6-nitroquinoxaline (1) undergoes displacement reactions with 1-methylpiperazine in the hot to give the bis-derivative (2) and at 30°C selectively at position-2 to afford the mono-derivative (3). Structure-proof for the latter involves transformation of 3 through hydrazine derivative (4). to the traizoloquinoxaline (5) and its 1-phenyl derivative (6) and comparison of the chemical shifts of protons at C-9 in the pair.