Synthesis and Crystal Structures of 3,3,6,6-tetramethyl-9-(2,4-dichlorophenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione and 3,3,6,6-tetramethyl-9,10-di(4-methoxyphenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione

The title compounds 3,3,6,6-tetramethyl-9-(2,4-dichlorophenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione 1 (C₂₃H₂₅Cl₂NO₂, Mr = 418.34) and 3,3,6,6-tetramethyl-9,10-di(4-methoxy-phenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione 2 (C₃₁H₃₅NO₄, Mr = 485.60) were synthesized and crystallized. The crystals of compound 1 are monoclinic, space group P2₁/c, a = 9.826(3), b = 19.866(5), c = 11.471(3) ?, β = 111.929(4)°, Z = 4, V = 2077(1) ?³; The compound 2 crystallizes in space group P2₁/c, with cell parameters a = 12.089(2), b = 11.447(2), c = 19.742(3) ?, β = 101.00(1)°, V = 2681.8(8) ?³ and D _calc = 1.203 g/cm³ for Z = 4. X-ray analysis reveals that atoms C(1), C(6), C(7), C(8), C(13) and N(1) form a 1,4-dihydropyridine ring in compound 1, which adopts half-chair conformation. In compound 2 the atoms C(1), C(6), C(7), C(8), C(13) and N form a 1,4-dihydropyridine ring which adopts boat conformation. In addition, the two outer six-membered rings display half-chair conformations in the crystal structures 1 and 2.