Reações de enonas trialometilsubstituídas com aminas e diaminas: Síntese de análogos do etambutol

Abstract

A series of 5,5,5-trifluoro-3-methyl-(alkylmethylamino)-pentane-1,4-diols, 5,5,5-trifluoro-3-methyl-(arylmethylamino)-pentane-1,4-diols and N,N-bis[5,5,5- trifluoro-3-methyl-(alkylmethylamino)]-pentane-1,4-diols were obtained from the reaction of 3-trifluoroacetyl-4,5-dihydrofuran with amines and diamines and subsequent reduction reaction using sodium borohydride (NaBH4) as a reducing agent. For the synthesis of amino alcohols derived from aryl amines, an equimolar amount of triethylamine was used in the first reaction step, providing better yields. The amino alcohols were obtained as diastereoisomeric mixtures, in the form of oil and with yields from moderate to good (50-83%). This work also presents the synthesis of β-dienamino ketones from the condensation of diamines with trihalomethylsubstituted enones using a simple and efficient method. The yields obtained were excellent and ranged from 75-98%. The trihalomethylsubstituted enones used as starting reagents were synthesized by acylation of acetals or enol ethers with trifluoroacetic anhydride or chloride trichoroacetil.