Cyanamide → 7,8-Dihydro-6H-indeno[5,6-e][1,2,4]triazin-3-amine 1-Oxide

Participants

Reaction Conditions

Reaction Steps

A mixture of amine 2 (21.67 g, 121.6 mmol), cyanamide (20.45 g, 486 mmol) and Et2O (10 mL) were mixed together at 80° C., cooled to ca. 50° C., cHCl (20 mL) added dropwise, during which a vigorous reaction occurred, and the mixture was heated at 80° C. for 1 h. The mixture was cooled to 50° C., 7.5 M NaOH solution added until the mixture was strongly basic and the mixture stirred at 100° C. for 8 h. The mixture was cooled, diluted with water (500 mL), and the yellow/green precipitate filtered. The precipitate was washed with water (3×50 mL), washed with ether (3×30 mL) and dried to give crude material (20.93 g, 85%), which can be used without further purification. The material was purified by chromatography, eluting with a gradient (0-5%) of MeOH/DCM, to give 1-oxide 19 (16.72 g, 68%) as a yellow powder: mp (MeOH/DCM) 270-272° C.; 1H NMR [(CD3)2SO] δ 7.92 (s, 1H, H-9), 7.33 (s, 1 H, H-5), 7.11 (br s, 2H, NH2), 2.91-2.99 (m, 4H, H-6, H-8), 2.01-2.09 (m, 2H, H-7); 13C NMR [(CD3)2SO] δ 159.9, 154.0, 148.5, 142.5, 128.7, 119.8, 113.8, 32.4, 31.6, 25.2. Anal. calcd for C10H10N4O: C, 59.4; H, 5.0; N, 27.7. Found: C, 59.4; H, 5.1; N, 27.8%.

Provenance & Evidence