STRUCTURE OF 2-(2,4-DIMETHOXYBENZOYL)FURAN-3-CARBOXYLIC ACID

C14H12O6, M(r) = 276.24, orthorhombic, P2(1)2(1)2(1), a = 18.48 (1), b = 9.52 (1), c = 7.55 (1) angstrom, V = 1328.27 angstrom 3, Z = 4, D(x) = 1.380 g cm-3, lambda(Mo K-alpha) = 0.7107 angstrom, mu = 0.69 cm-1, F(000) = 576, T = 290 K, R = 0.061 for 1330 unique observed [I/sigma(I) > 3.0] reflexions. Internal hydrogen bonding between carboxyl O-H(1) and ketonic O(1) [O...O = 2.575 (9) angstrom] causes distortion of the exocyclic angles of the furan ring at C(8) and C(1). The molecule is twisted about the C(1)-C(7) bond such that O(2) and O(5) are separated by 2.811 (6) angstrom, slightly more than the sum of their van der Waals radii.