2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylates, their preparation and use
2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylates of formula (I): wherein one of R 1 and R 2 can be hydrogen. R 1 and R 2 , if not hydrogen, and in each case independently of one another, are selected from straight-chain, branched or cyclic C 1-22 -alkyl groups, preferably C 1-12 -alkyl groups, C 6-12 -aryl groups, C 6-18 -aralkyl groups and C 6-18 -alkaryl groups, wherein R 1 and/or R 2 , in each case independently of one another, may comprise at least one additional functional group, selected from hydroxyl groups, ether groups, ester groups, epoxy groups, and double bonds, and wherein R 2 may be substituted with up to 10, preferably with 1 to 5, and in particular with 1 or 2 further 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylic groups. The 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylates can be prepared by reacting 2-oxo-1,3-dioxolane-4-carboxylic acid with epoxides and can be used for the preparation of hydroxyurethanes through reaction with amines, such as amine hardeners. Moreover, they can also be used as end groups for the blocking of amines.
1. 2-Hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate of formula (I)
wherein one of R 1 and R 2 is optionally hydrogen, wherein R 1 and R 2 , if not hydrogen, in each case independently of one another, are selected from straight-chain, branched or cyclic C 1-22 -alkyl groups, C 6-12 -aryl groups, C 6-18 -aralkyl groups and C 6-18 -alkaryl groups,
wherein R 1 and/or R 2 , in each case independently of one another, may comprise at least one additional functional group, selected from hydroxyl groups, ether groups, ester groups, epoxy groups, and double bonds,
and wherein R 2 is optionally substituted with up to 10 further 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylic groups of formula (1a)
wherein R 1 has the meaning given.
2. The 2-Hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate of claim 1 , wherein R 1 and R 2 , in each case independently of one another, are selected from methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, neo-pentyl, nhexyl, 2-ethyl-n-hexyl, cyclohexyl, phenyl, benzyl, polyether groups, polycarbonate groups, polyester groups, fatty acid ester groups, poly(meth)acrylate groups, and combinations thereof.
3. The 2-Hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate of claim 1 , comprising the glycerol ester moiety:
4. A process for the preparation of 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylates as defined in claim 1 , characterized in that 2-oxo-1,3-dioxolane-4-carboxylic acid of formula (1b)
is reacted with an epoxide of formula (1c)
wherein R 1 and R 2 have the meanings given, to give the 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate of formula (I).
5. The process of claim 4 , which is carried out in the presence of a catalyst selected from tertiary amines, organometallic compounds, and mixtures thereof.
6. The 2-Hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate of claim 1 , wherein R 1 and R 2 , if not hydrogen, in each case independently of one another, are selected from straight-chain, branched or cyclic C 1-12 -alkyl groups.
7. The 2-Hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate of claim 1 , wherein R 2 is substituted with 1 to 5 further 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylic groups of formula (1a).
8. The 2-Hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate of claim 1 , wherein R 2 is substituted with 1 or 2 further 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylic groups of formula (1a).
9. A process comprising reacting the 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate as defined in claim 1 with an amine to form a hydroxyurethane.
10. A process comprising blocking an amine with the 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate as defined in claim 1 as an end group.