NEW MATERIAL:A pyrophosphoric ester derivative shown by the formula I (A is aryl optionally replaced by one or more of lower alkyl, lower alkoxy and halogen; R1 is aryl, acryloyloxy lower alkyl, etc.).
EXAMPLE: A compound shown by the formula V.
USE: A restorative dental material for remedy. Being polymerized by light, heat, polymerization initiator, etc., and cured. A polymer having improved compression strength, hardness, etc. in a short curing time.
PROCESS: A compound shown by the formula II is reacted with POCl3 to give a compound shown by the formula III, which is reacted with an alcohol shown by the formula R1-OH to give a compound shown by the formula IV. The compound is subjected to hydrolysis and condensation through dehydrochlorination in the presence of water and a base, to give a compound shown by the formula I.
YOSHIDA SHINZOU
KOOMURA TAMOTSU
