Ql. Chu et al., A novel method for preparation of trifluoromethyl substituted 2,3-dihydro-1,4-diazepine and benzimidazole, SYN COMMUN, 30(4), 2000, pp. 677-687
Ethylenediamine reacted readily with 4-ethoxy-1,1,1-trifluoro-3-butene-2-on
e to form 5-trifluoromethyl-2,3-dihydro-1,4-diazepine in good yield. Under
the same reaction conditions o-phenylene diamine gave 2-trifluoromethyl ben
zimidazole and benzimidazole.