THE REACTION OF PHOSPHONIUM YLIDES WITH 1,2-BENZO[a]PHENAZINE-8,9-DIONE, NAPHTHO[2,1-b]FURAN-1,2-DIONE, BENZO[b]THIOPHENE-2,3-DIONE AND 1,2,3-INDANTRIONE

Abstract

When 1,2-benzo[a]phenazine-8,9-dione (1), was reacted with two molar amounts of phosphonium ylides (5), the corresponding dialkyl 1,2-dihydrobenzo[a]furo[3,2,h]phenazine-1,2-dicarboxylates (9) were obtained. Moreover, naphtho[2,1-b]furan-1,2-dione (2) and benzo[b]thiophene-2,3-dione (3) were converted by reaction with ylides (5) into alkyl 2-oxonaphtho[2,1-b]furan-1(2H)-ylidene acetate (10) and alkyl (2-oxobenzo[b]thien-3(2H)-ylidene)acetate (11). On the other hand, the spiro-compounds (13) were isolated from the reaction of 1,2,3-indantrione (4) and Wittig reagents (5). The structure of the new compounds 9, 10, 11 and 13 was confirmed on the basis of elemental analysis and spectral studies.