Nitration of hexafluorobutadiene with nitrogen dioxide

Summary

• 1. The nitration of hexafluorobutadiene with nitrogen dioxide was studied, and some chemical properties of the nitration products were examined.

• 2. The main reaction products, both in the liquid and in the gas phase, were hexafluoro-1,4-dinitro-2-butene and hexafluoro-4-nitro-2-buten-1-ol nitrous ester.

• 3. On hydrolysis, hexafluoro-4-nitro-2-buten-1-ol nitrous ester gives tetrafluoro-4-nitrocrotonic acid, and on treatment with alcohols or ammonia it gives the esters or amide of this acid. The following derivatives of tetrafluoro-4-nitrocrotonic acid were synthesized: the methyl, ethyl, isopropyl, butyl, isopentyl, and cyclohexyl esters, the acid chloride, the amide, the nitrile, and the silver and potassium salts.

• 4. In addition to the main reaction, some side reactions occur under nitration conditions. These include the oxidation of the primary products of the nitration of hexafluorobutadiene at the double bond with formation of difluoronitroacetyl fluoride.