Synthesis and crystal structure of 2-amino-3-cyano-4-(4-fluorophenyl)-4H-benzo[h]chromene

The title compound (C20H23FN2O.C3H7NO) was obtained by the reaction of 4-fluorbenzaldehyde, malononitrile and 1-naphthol in ethanol in the presence of piperidine and by recrystallization from DMF and water. Its structure was characterized by elemental analysis, IR, H-1 NMR and X-ray single-crystal diffraction analysis. The crystal belongs to monoclinic, space group P2(1)/n with a = 6.365(1), b = 10.620(2), c = 29.122(6) Angstrom, beta = 92.00(1)degrees, V = 1967.3(6) Angstrom(3), M-r = 389.42, Z = 4, D-c = 1.315 g/cm(3), mu(MoKalpha) = 0.092mm(-1) and F(000) = 816. The structure was solved by direct methods and refined by full-matrix least-squares techniques to the final R = 0.047 and wR = 0.1053. X-ray analysis reveals that the C(1), C(2), C(3), C(4), C(5) and O(1) atoms form a six-membered ring in which the distance of C(1)-C(2) is 1.346(3) Angstrom, indicating it is a C=C double bond. In addition, this six-membered ring is of boat confirmation.