Crystal polymorphism of methyl 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl)-α-d-glucopyranouronate
Hayes, John A.
Eccles, Kevin S.
Elcoate, Curtis J.
Daly, Carla A.
Lawrence, Simon E.
Moynihan, Humphrey A.
The polymorphism of the glycoside donor methyl 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl)-α-d-glucopyranouronate (1) has been investigated. Two polymorphic forms (labelled Forms I and II) have been elucidated and fully characterised by DSC, PXRD and single crystal analysis, both crystallizing in the space group P21. Form I was obtained by crystallization from a wide range of solvents, while Form II was obtained only from ethyl acetate or isopropanol on certain occasions. Unit cell dimensions for Form I are a 14.0292(12), b 8.9641(8), c 16.8580(14) Å, β 94.285(2)°, and for Form II a 11.266(3), b 6.8889(17), c 13.921(4) Å, β 101.161(6)°. Z’ is 2 for Form I and 1 for Form II. Form I displays two moderate intermolecular hydrogen bonds in the unit cell whereas Form II shows no moderate hydrogen-bonding motifs. All three molecules in the two polymorphs differ significantly in their conformations, especially with respect to the methyl carboxylate and trichloroacetimidoyl groups
Methyl 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl)-α-d-glucopyranouronate , Polymorphism , Imine hydrogen bonding
HAYES, J. A., ECCLES, K. S., ELCOATE, C. J., DALY, C. A., LAWRENCE, S. E. & MOYNIHAN, H. A. 2013. Crystal Polymorphism of Methyl 2,3,4-tri-O-acetyl-1-O-(trichloroacetimidoyl)-α-d-glucopyranouronate. Journal of Chemical Crystallography, 43, 138-143. DOI: http://dx.doi.org/10.1007/s10870-013-0397-y
© Springer Science+Business Media New York 2013. The final publication is available at Springer via http://dx.doi.org/10.1007/s10870-013-0397-y