N-methyl-DL-aspartic acid monohydrate

The title compound, C(5)H(9)NO(4).H(2)O, has been synthesized and crystallized. It crystallizes in Cc with one molecule in the asymmetric unit. The compound is found in its zwitterionic form. D and L forms of the compound are linked in the crystal via O-H...O and N-H.O hydrogen bonds, both directly between the aspartic acid-derivative entities and to the crystal water molecule. A weak intramolecular N-H...O interaction is found. The carbon skeleton is slightly twisted with C-C-C-C = 166.83 (11) degrees. A comparison with other derivatives of aspartic acid shows only two rotamers--one with a near planar carbon skeleton and one with a significantly twisted carbon skeleton.