Polyaddition of bis(seven-memebered cyclic carbonate) with diamines:a novel and efficient synthetic method for polyhydroxyurethanes

摘要

This article deals with the polyaddition of a novelbis(seven-membered cyclic carbonate),1,2-bis[3-(2,3-dioxepan-2-one-5-yl)-propylthio]ethane,with the diamines,4,9-dioxa-1,12-dodecanediamine andp-xylylenediamine.The polyaddition was carried out at 30-70degC for 6-24 h in dimehtyl sulfoxide to obtain the corresponding polyhydroxyurethanes with number-average molecular weithts of 10,900-35,700 in good yields.The reaction of a monofunctional seven-membered cyclic carbonate,5-Allyl-1,3-dioxepan-2-one (7CC),with monoamines was also carried out to examine the reactivity in comparison with that of six-and five-membered cyclic carbonates.The reaction rate constants of 7CC with n-hexylamine and benzylamine were estimated to be 48.5 and 11.0 L/molcentre doth,respectivley,in dimethylsulfoxide-d_6(initial reagent concentration=1M) at 30degC.The seven-membered cyclic carbonate ring was 2.98 and 5.82 kcal/mol mor estrained than those of the six-and five-membered cyclic carbonates,respectivley,according to a semiempirical molecular orbital calculation with the PM3 Hamiltonian.