Abstract Two polymorphs of 3-(dimethylamino) benzoic anhydride have been determined by single crystal X-ray diffraction analysis. Polymorph (1) is triclinic (P1–, a 7.112 (3), b 9.289 (4), c 13.364 (5) Å, a 96.39 (2), b 104.04 (2), g 107.59 (2), V 800.0 (6) Å 3, Z 2) with the full molecule in the asymmetric unit, whereas polymorph (2) is monoclinic (C2/c, a 10.892 (3), b 11.855 (4), c 13.164 Å, b 112.14 (3), V 1574.5 (9) Å 3, Z 4) with the central oxygen atom ...
