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°.