A gas phase, two stage process for the production of polypropylene impact copolymer wherein fouling of a second stage recycle loop and heat exchange unit incorporated therein is reduced by the addition to substantially gaseous material passing through the loop of a small amount of an alkylene compound.
Reaction of α-Bromo Enones with 1,2-Diamines. Cascade Assembly of 3-(Trifluoromethyl)piperazin-2-ones via Rearrangement
作者:Alexander Yu. Rulev、Vasiliy M. Muzalevskiy、Evgeniy V. Kondrashov、Igor A. Ushakov、Alexey R. Romanov、Victor N. Khrustalev、Valentine G. Nenajdenko
DOI:10.1021/ol401041f
日期:2013.6.7
A facile one-pot synthesis of 3-trifluoromethylated piperazin-2-ones has been achieved by the treatment of trifluoromethyl 2-bromo enones with N,N'-disubstituted ethylenediamines in trifluoroethanol. The mechanism of this unexpected reaction is discussed in terms of multistep processes involving formation of captodative aminoenone as a key intermediate. The unique influence of trifluoromethyl group on the reaction path was demonstrated.