Synthesis and Crystal Structure of 1,7,7-Trimethyl-4-(4-methoxyphenyl)-4,6,7,8-tetrahydroquinoline-2,5(1H,3H)-diones under Microwave Irradiation

The title compound (C19H23NO3) was synthesized by the one-pot reaction of p-me- thoxybenzaldehyde, Meldrum’s acid, dimedone and CH3NH3Cl (NaOAc) in ethanol under micro- wave irradiation without catalyst and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 8.7462(10), b = 17.7367(19), c = 11.5959(14) ?, β = 110.981(3)°, V = 1679.6(3) ?3, Z = 4, Dc = 1.239 g/cm3, μ(MoKα) = 0.083 mm–1, F(000) = 672 and Mr = 313.38. The structure was refined to R = 0.0530 and wR = 0.1216. X-ray analysis reveals that the dihedral angle between plane 1 (N(1), C(1), C(2), C(3)) and plane 2 (C(1), C(2), C(6), C(7), C(9)) is 3.64°, andt hat between plane 2 and plane 3 (C(11)~C(16)) is 85.33°.