NUCLEOPHILIC SUBSTITUTIONS OF 2-CHLORONAPHTHO[2,3-B]FURAN-4,9-DIONE WITH AMINES

2-Chloronaphtho[2,3-b]furan-4,9-dione 4 was allowed to react with pyrr olidine to produce 2-(1-pyrrolidinyl)naphtho[2,3-b]furan-4,9-dione 8 i n 64% yield. In a similar manner, the reaction of 4 with cyclic amines (piperidine, morpholine, 4-substituted piperazines, etc.) gave the de sired compounds. 2-Dimethylaminonaphtho[2,3-b]furan-4,9-dione 20 and 2 -propylaminonaphtho[2,3-b]furan-4,9-dione 23 were obtained from the re actions of 4 with amines in 67% and 48% yields, respectively. Furtherm ore, the reactions of 4 with acyclic amines (diethylamine, dipropylami ne, isopropylamine, butylamine, etc.) gave the desired compound. Compo und 4 was treated with sodium azide to give 2-azidonaphtho[2,3-b]furan -4,9-dione 28 in 42% yield. All these nucleophilic substitutions were carried out at room temperature. It was found that 4 showed high react ivity for amines. Unexpectedly, 2-morpholinonaphtho[2,3-b]furan-4,9-di one 13 was obtained from the reaction of 4 with 1-morpholino-1-cyclohe xene.