“…Caled for C24H20N2O2S: C, 71.97; , 5.03; N, 6.99. Found: C, 72.01; , 5.20; N, 7.00. cis-and irans-5-Methyl-1,3-diphenyl-1,3-dihydrothieno [3,[4][5]quinoxaline 2,2-Dioxide (5).-A solution of 12.5 g (0.042 mol) of A6 in 70 ml of absolute ethanol and 5.0 g (0.042 mol) of 2,3diaminotoluene in 30 ml of the same solvent was refluxed for 2 hr, cooled to room temperature, and filtered. The residue (14.0 g, 87%) was washed with ethyl ether and recrystallized (Darco) once from nitromethane to give 5 as a hard yellow powder: mp 230-230.5°dec; ir 7.54, 8.60, 8.78, and 8.86 µ (S02); uv max 220 µ (e 27,500), 244 (31,200), 304 (5800), and 320 (6900); nmr (CDC13) 8.0-7.2 (m, 14, aromatic), 5.83 (s, 4, CH), 2.71 (s, 3, CHS), and 2.66 (s, 3, CH3).…”