| 摘要 |
A process for making 2,5-morpholinediones of structure (I), wherein each R is independently hydrogen, C1-C12 hydrocarbyl, or substituted hydrocarbyl and at least one R is C1-C12 hydrocarbyl or C1-C12 substituted hydrocarbyl, by reacting an ester of free acid of an N-(.alpha.-hydroxyacyl)-.alpha.- amino acid substrate of structure (II) wherein each R and R3 is independently hydrogen, C1-C12 hydrocarbyl or C1-C12 substituted hydrocarbyl and wherein at least one R is C1-C12 hydrocarbyl or C1-C12 substituted hydrocarbyl, over a fixed bed catalyst, the reaction being carried out at about 150.degree.C to about 350.degree.C, followed by collection of the effuent product. Such morpholinediones are useful as precursors for the preparation ofdepsipetide polymers and copolymers.
|
