6,9-Dioxa-3,12-diazatetradecanedioic acid, 3,12-bis(2-ethoxy-2-oxoethyl)-, diethyl ester 99590-87-1 Diethyl 3,12-bis(2-ethoxy-2-oxoethyl)-6,9-dioxa-3,12-diazatetradecanedioate Egta ethyl ester