STRUCTURE OF ETHYL 2-(2-AMINO-3-ETHOXYCARBONYL-4H-CHROMEN-4-YL)-2-CYANOACETATE

C17H18N2O5, M(r) = 330.35, monoclinic, P2(1)/n, a = 21.335 (2), b = 8.516 (1), c = 9.273 (1) angstrom, beta = 93.645 (1)-degrees, V = 1681.44 (5) angstrom3, Z = 4, D(m) = 1.330, D(x) = 1.305 Mg M-3, lambda(Cu Kalpha) = 1.5418 angstrom, mu = 0. 77 mm-1, F(000) = 696.00, T = 300 K, final R = 0.059 for 3184 observed reflections [I > 3sigma(I)]. The dihydropyran ring makes a dihedral angle of 14.6 (3)-degrees with the benzene ring and is puckered. The ethoxycarbonyl group attached to C(3) makes a dihedral angle of 13.9 (3)-degrees with the chromene ring but the 4-(1-ethoxycarbonyl) group is rotated about C(4) by 81.1 (4)-degrees. The C-C=N chain is almost linear and makes a dihedral angle of 48.4 (3)-degrees with the C(4) ethoxycarbonyl group. The molecule exhibits intramolecular hydrogen bonding between the amino group at C(2) and the carbonyl O atom of the C(3) ethoxycarbonyl group. Intermolecular N-H...O bonds link the molecules across the centre of symmetry.