Syntheses of Furo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines and Furo[2`,3`: 5,6]-pyrimido[3,4-b][2,3-e]indolo[1,2,4]triazine as a New Ring System

Nasser Hassan
2000 Molecules  
2-Amino-4,5-di-(2-furyl)furan-3-carbonitrile (1) reacted with triethyl orthoacetate to afford the corresponding 2-ethoxyimine derivative (2). The latter compound reacted with phenyl hydrazine, p-fluorobenzylamine and sodium hydrogen sulfide, respectively, to afford the corresponding furo[2,3-d]pyrimidine derivatives (3-5). Compound 1 also reacted with carbon disulfide and phenyl isocyanate to afford 5,6-di-(2-furyl)-1H-4H-furo[2,3-d]-[1,3thiazin]-4-imino-2-thione (6) and
more » ... di-(2-furyl)-1H-3H-3-phenylfuro[2,3-d]pyrimidin-4imine-2-one (7), respectively. Treatment of compound 2 with hydrazine hydrate at 0 o C afforded compound 8, while on boiling 5,6-di-(2-furyl)-3H,4H-4-imino-2-methylfuro-[2,3d]pyrimidin-3-amine (9) was isolated. Treatment of 9 with carbon disulfide, cyanogen bromide, ethyl cyanoacetate, diethyloxalate and triethyl orthoformate gave the corresponding furo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines (10-14). Reaction of 9 with isatin and N-acetyl isatin gave the condensation products 15 and 16 respectively.
doi:10.3390/50600826 fatcat:5iqgrvov6var3c737do7eggise