The present invention suggests 2-oxo-1,3-dioxolane-4-carboxamides of formula (I), in which R2 can be, inter alia, an n-valent radical (n>1) which is substituted with n−1 further 2-oxo-1,3-dioxolane-4-carboxamide groups of general formula (II), to processes for the preparation of these 2-oxo-1,3-dioxolane-4-carboxamides, to processes for the preparation of the 2-oxo-1,3-dioxolane-4-carboxylic acids of formula (III), which are suitable starting materials for the above processes, and to the use of said 2-oxo-1,3-dioxolane-4-carboxamides for the preparation of (poly)hydroxyurethanes, -hydroxycarbonates and -hydroxysulfanylformates, and also as end groups for the blocking of amines.