Fluorinated acetylenes. Part III. Some reactions of 3,3,3-trifluoro-NN-bistrifluoromethylprop-1-ynylamine and perfluoro-1,2-bisdimethylaminoacetylene

Abstract

3,3,3-Trifluoro-NN-bistrifluoromethylprop-1-ynlamine reacts with bromine or hydrogen bromide under photochemical conditions to give the corresponding trans-addition product and another 1:1 adduct, probably 1-bromo-3,3,3-trifluoro-NN-bistrifluoromethylprop-1-enylamine, present in the ratio 93:7. The acetylene undergoes hydrogenation and acid-catalysed hydration to yield cis-3,3,3-trifluoro-1-methoxy-NN-bistrifluoromethylprop-1-enylamine in the ratio 96:4.

Perfluoro-1,2-bisdimethylaminoacetylene reacts with bromine in the dark or under photolytic conditions to give 1,2-di(bistrifluoromethylamino)-1,2-dibromoethylene (probably trans). The photochemical reaction with hydrogen bromide gives 1,2-di(bistrifluoromthylamino)-1-bromoethylene and hydrogenation yields cis-1,2-di(bistrifluoromethylamino)ethylene. Attempted acid-catalysed hydration, reaction with methanol under neutral or acid-catalysed conditions, and reaction with sodium methoxide in methanol were unsuccessful.

N-Bromobistrifluoromethylamine reacts with 3,3,3-trifloropropyne to give four 1:1 adducts of which cis- and trans-2-bromo-3,3,3-trifluoro-NN-bistrifluoromethylprop-1-enylamine are the major products.