| abstract |
Esters of formula (I) (R1 = satd., opt. branched 3-18C hydrocarbon chain; n = 1 or 2) are prepd. by (1) reacting aliphatic hydroxy cpd. of formula HO-R1-OH (II) with diaryl carbonate of formula Ar1-OC(:O)-Ar2 (III) (Ar1, Ar2 = Ph, Ph substd. by alkyl, alkoxy, halogen or CN, or naphthyl) in presence of transesterification catalyst with splitting off of a phenol; (2) tempering; and (3) depolymerising. USE/ADVANTAGE - By insertion of tempering stage, (I) are obtd. in good yield and high purity, substantially free from cpds. with acidic H atoms, and can be used directly as monomers for anionic ring-opening polymerisation to form homo- and co-polymers with narrow mol.wt. distribution (DE3607627, 3700193, 3911557). |