Síntese de espiro[cromeno[4,3-d]pirimidinas-5,1 -cicloalcano] e 5,6-diidrobenzo[h]quinazolinas trifluormetil substituídas

Abstract

The present dissertation initially describes new methods for the synthesis of 4-(trifluoromethyl)-5,6-dihydrobenzo[h]quinazolines and 4-(trifluoromethyl)spiro[chromeno[4,3-d]pyrimidines-5,1'-cycloalkane], as new trifluoromethyl substituted heterocyclic systems. Cyclocondensation reactions type [3 + 3] involving 2,2,2-trifluoro-1-(1-methoxy-3,4-dihydronaphthalen-2-yl)ethanone and five amidines [NH2-(C=NH)R] conducted to the synthesis of a new series of five examples of 2-substituted 4-(trifluoromethyl)-5,6-dihydrobenzo[h]quinazolines in 40-70% yield, where R = 2-substituent = H, methyl, phenyl, NH2 or SCH3. In sequence, a new series of nine unpublished 4-(trifluoromethyl)spiro[chromeno[4,3-d]pyrimidines-5,1'-cycloalkane] were obtained in 73-95% yield from cyclocondensation reactions type [3 + 3] involving 2,2,2-trifluoro-1-(4-methoxyspiro[chromene-2,1'-cycloalkane]-3-yl)ethanones and some amidines. These new spiro-heterocyclic structures have a methyl, phenyl or NH2 substituent attached to the position-2 and a 5-, 6- or 7-membered cycloalkane at the spiroposition-5, simultaneously. Finally, to demonstrate the synthetic utility of the 2-amino substituent attached to the obtained heterocycles, N-derivatization reactions of 4-(trifluoromethyl)-5,6-dihydrobenzo[h]quinazolin-2-amine and 4-(trifluoromethyl)spiro[chromeno[4,3-d]pyrimidine-5,1'-cyclopentan]-2-amines employing 2,5-dimethoxytetrahydrofuran in acetic acid medium (Clauson-Kaas reaction) by two methods are described. The first method followed a two-step reaction procedure (35-55%) and the second an "one pot" method (45-55%). The "one-pot" method was the most advantageous by some experimental aspects. However, both methods allowed an efficient conversion of the 2-amino group into the 2-(1H-pyrrol-1-yl) substituent and the obtainment of four new examples of 2- (1H-pyrrol-yl)-substituted heterocyclic molecules.