(5RS)‐5‐(4‐Methoxyphenyl)‐2‐(methylsulfanyl)benzo[g]pyrimido[4, 5‐b]quinoline‐4, 6, 11(3H, 5H, 12H)‐trione, with Z′ = 3, forms a three‐dimensional hydrogen‐bonded framework containing five types of hydrogen bond. Issue 1 (15th January 2014)