Search

The reaction of methoxycarbonylmethylene 2b- and ethoxycarbonylmethylene 2c-triphenylphosphoranes with substituted 2-amino-1,4-naphthoquinones 1a-c afforded the new pyrroline-ylidphosphoranes 3b-3g via 1,2- and 1,4-addition reactions. On the other hand, 2-dimethylamino-1,4-naphthoquinone 1d reacts with cyanomethylenetriphenylphosphorane 2d to give adduct 4. Mechanisms accounting for the formation of the new products are discussed.

Diethyl phosphite 2a reacts with N- (phenylsulfonyl) - 1,4 - benzoquinone monoimine 1a to give 1,4-diethyl [(2-hydroxy-5-[(phenylsulfonyl) amino ] phenyl] [sphosphonate 3a, diethyl (1-hydroxy -4- [ ( phenylsulfonyl ) imino ] -2,5-cyclohexadiene )] phosphonate 3b and amide 3c , respectively. When quinone monoimine 1a was reacted with dimethyl and diisopropyl phosphites (2b,c), the corresonding dialkyl phosphonate adducts (bd3e) and (bd3f) were obtained. Whereas quinone monoimine (bd1b) is reduced mainly to amide (bd4b) when treated with diethyl phosphite (bd2a) , it reacts with dimethyl phosphite (bd2b) to give the dialkyl phosphonate adduct (bd4a) together with amide (bd4b) . Possible reaction mechanism are considered and the structural assignments are based on compatible analytical and spectroscopic results.

Wittig reagents (1a,c) react with phthalimidobenzoic acid azide (2a) to give the new products 3a, 3b, 3c, and 5, respectively. On the other hand, methylenetriphenylphosphorane (1b) reacts with azides (2a,b) to afford the corresponding 1,5-disubstituted-1,2,3-triazoles (4,6). Structural reasoning for the new products was based on compatible analytical and spectral data.