Reaction between naphthols and dimethyl acetylenedicarboxylate in the presence of phosphites. Synthesis of stable oxa-2 lambda 5-phosphaphenanthrenes, and benzochromene derivatives.
The reaction of dimethyl acetylenedicarboxylate (DMAD) with 2-naphthol in the presence of trimethyl or triphenyl phosphite leads to stable dimethyl oxa-2 lambda 5-phosphaphenanthrene derivatives in good yields. The reaction of DMAD and trimethyl phosphite in the presence of 1-naphthol or 8-hydroxyquinoline leads to dimethyl 2-(dimethoxyphosphoryl)-3-(1-hydroxy-2-naphthyl)succinate or dimethyl 2-(dimethoxyphosphoryl)-3-(8-hydroxyquinolin-7-yl)-succinate in excellent yields. Using triethyl phosphite and DMAD in the presence of 2-naphthol or 1-naphthol produces methyl 3-oxo-2,3-dihydro-1H-benzo[f]chromene-1-carboxylate or methyl 2-oxo-3,4-dihydro-2H-benzo[h]-chromene-4-carboxylate in excellent yields.
Yavari
Issa
I
Department of Chemistry, University of Tarbiat Modarres, PO Box 14115-175, Tehran, Iran. isayavar@yahoo.com
Anary-Abbasinejad
Mohammad
M
Hossaini
Zinatossadat
Z