Novel cycloaddition products from the reaction of 2,5-dichloro-1,1,1,6,6,6-hexafluoro-3,4-diazahexa-2,4-diene with cycloalkenes, cyclodienes and cycloheptatriene, and of hexafluoroacetone azine with cycloheptatriene

Article abstract of DOI:10.1016/S0022-1139(00)80391-7

Thermal reaction (20-70 deg C) of the dichloroazine CF3CCI=N-N=CCICF3 (2) with cyclopentene (in CH2CI2 solwent), cycloheptene, indene, acenaphtylene, 2,3-dihydrufuran, 2,3-dihydropyran, norbornadiene, cyclopentadiene and dicyclopentadiene gives as the major product in each case the rearranged <3+2> cycloadduct (3) containing a CF3CCI2 group; hydrolisys (CF3CCI2 --> CF3CO) to give the amide (4) takes place on attempted chromatographic purification on silica gel.With cyclopentene the rearrangad cyclopentadiene <3+2> cycloadduct (3b) is also formed, while other products obtained by chromatographic separation from the 2,3-dihydropylan reaction are the 5,6-dihydropyran-3-yl azine (5), the hydrozone (8) and equimolar quantities of 5,6-dihydropyran-3-yl trifluoromethyl ketone (6) and the chlorohydrazone (7) possible arising via hydrolysis of the 1:2 adduct (16).The reaction of azine 2 with cycloheptatriene at 70 deg C gives a complex mixture, in which the major products are the rearranged <3+6> cycloadduct (31) and the dehydrochlorinated <3+2> cycloadduct (10) and (11) containing a CF3CHCI group.The corresponding reaction with hexafluoroacetone azine (1) at 70 deg C affords the criss-cross <3+2> cycloadduct (22), the bis-ene adduct (23) and its oxidation product, the azo compound (24), and the <3+6> cycloadduct diaziridine (25).