5.6- Dichloro-3-nitro-2-pyrazinamine

Dichloro-3-nitro-2-pyrazinamine and ethyl 3-aminocrotonate gave 5-(2-amino-1 -ethoxycarbonylprop-1 -enyl)-6-chloro-3-nitro-2-pyrazinamine (107) (Et3N, Pr OH, 20°C, 16 h 62%).788... 

Dichloro-3-nitro-2-pyrazinamine (60, R = NH2) gave 2-bromo-5,6-dichloro-3-nitropyrazine (60, R = Br) (Bu CH2ONO, excess CHBr3, reflux, 8 h then more Bu CH2ONO J, reflux, 10 h —50%, crude product mechanism ).1313... 

Amino-5,6-dichloro-2-pyrazinecarboxylic acid (1) gave 5,6-dichloro-3-nitro-2-pyrazinamine (2) (H2S04—HN03, 15 —> 20°C, 4 h 46% C02 f during the reaction).607,1313... 

There is little recent information in this area. The tine structure of 3-acetoxy-l, 4-dinitro-2-piperazinol (14) has been elucidated by X-ray analysis.1212 Treatment of 5,6-dichloro-3-nitro-2-pyrazinamine (15) with refluxing ethanolic sodium cyanide for 4 days induced displacement of the nitro by a cyano group as well as ethanoly-sis of one chloro substituent to afford 3-amino-6-chloro-5-ethoxy-2-pyrazinecar-bonitrile (16) in 55% yield.1313 L-Methyl-4-(/>nitrobenzoyl)pipcrazine (17) gave I -(/ -aminobenzoyl)-4-methy I piperazine (18) (75%) on refluxing in ethanolic hydrazine hydrate with a little Raney nickel catalyst for 6 h 135, cf 1032 other reduction procedures have been reported.496,1741... 

---