Selective Preparation of 3,4,5-Trinitro-1H-Pyrazole: A Stable All-Carbon-Nitrated Arene



original image

Lowering the boom: 3,4,5-trinitro-1H-pyrazole (TNP, see picture) has been prepared by the unexpected nitration of 3,5-dinitropyrazole with a super-electrophile generated from 20–30 % sulfuric oleum mixed with nitric acid. The remarkable stability of TNP results from the preservation of the ring geometry and the specific conformation of the nitro group at C4 which confers low acidity on the material.