Synthesis and conversions of 2-acetyl-5-methyl-4-nitrofuran. Isomerization and beckman rearrangement of the oxime

2-Acetyl-5-methyl-4-nitrofuran and 3,5-dinitro-α-methylfuran were obtained by the reaction of 70% nitric acid with 2-acetyl-5-methylfuran, its oxime and semicarbazone in concentrated H2SO4. ω-Bromonitro ketone and a series of 5-methyl-4-nitro-2-furyl-substituted azaheterocyclic compounds based on it were obtained.