abstract |
Title esters are of formula: (in which, each R1 is 1-8 C alkoxy; R2 is R1, Ph or 2-8 C alkyl; X is CH2 or CO), and are prepd. by eliminating alkyl chloride from trialkyl phosphites or phosphinic esters and ring-halogenated terephthalyl chloride or p-xylylene dichloride. |