SYNTHESIS OF 4-METHOXYPHENYL-SUBSTITUTED FURO-FUSED DERIVATIVES

Methyl methoxyphenyl)-4H-furo[3,2-b]pyrrole-5-carboxylate was prepared hy thermolysis of the corresponding methyl 2-azido-3-[5-(4-methoxyphe nyl)-2-furyl]propenoate. 4-Methyl and 4-benzyl derivatives were obtain ed using phase-transfer catalysis conditions. Methyl methoxyphenyl)-4H -furo[3,2-b]pyrrole-5-carboxylate with hydrazine hydrate yielded corre sponding carbohydrazide, which by reaction with triethyl orthoformate or -acetate and -propionate afforded 5-substituted furo[2',3':4,5]pyrr olo[1,2-d][1,2,4]triazin-8-ones giving with phosphorus(V) sulfide thio nes, reacting with hydrazine to corresponding hydrazono derivatives. T he last ones with triethyl orthoformate underwent cyclization reaction s leading to rolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines.