Acetonitrile → 2-Amino-n-(1,4-dioxo-1,2,3,4-tetrahydrophthalazin-5-yl)acetamide

Participants

Reaction Steps

2-Chloro-N-(1,4-dioxo-1,2,3,4-tetrahydrophthalazine-5-yl)acetamide (300 mg; 1.182 mmol) was suspended in ammonium hydroxide (7 ml) and stirred slowly in a vial at 4 C for 8 days (30%). The reaction mixture was transferred into a flask and hot water (25 ml) was added to the reaction mixture, filtered, and the filtrate was collected. The initial pH (12) of the filtrate was adjusted to 5.38 by slow addition of acetic acid to obtain the intermediate. The beige colored solid was filtered, rinse with water (10 ml), washed with methanol (50 mL), and finally with ether (50 ml), and then dried under reduced pressure. The residue was suspended in hydrazine (30% in water, 22 ml) and heated to dissolve the precipitates. The contents were allowed to cool to RT, pH was adjusted to 4.8, and precipitates were obtained upon cooling. The resultant precipitates were filtered, washed with water, methanol (cold), ether, and then dried under reduced pressure to obtain 2. 1H NMR (300 MHz, DMSO-d6) δ: 8.86 (d, 1H), 7.85 (t, 1H), 7.60 (d, 1H), 3.33 (s, 2H), 2.16 (s, 3H, Methyl for Acetic Acid); ESMS: Calcd for C10H10N4O3: 234.0, Found, 235.0; HPLC: Purity was further analyzed on a C-18 column (Vydac) employing a mobile phase eluent gradient of 10-90% acetonitrile in water containing 0.1% TFA over 30 minutes with a flow rate of 1 mL/min, Rt=13.2 min.

Provenance & Evidence