Ethylenediaminetetraacetic Acid → 4,5-Diaminophthalonitrile

Participants

Reaction Conditions

Reaction Steps

A 50 mL round-bottom flask was charged with 2 (6.94 g, 19.3 mmol), and CuCN (6.91 g, 77.2 mmol, 4 eq), and a magnetic stirring bar. The vessel was capped with a septum and flushed with Ar for 10 min, and NMP (20 mL) was added. The vessel was heated to 120° C. for 3 h, then diluted with DMF (20 mL) and added to a hot aqueous solution of EDTA (88 g, 232 mmol, in 500 mL H2O) in a 1 L conical flask. Oxygen was bubbled through the mixture as it was stirred and heated for 2 h. After 2 h of this treatment, the dark heterogeneous mixture turned to a homogeneous green solution. The hot green solution was extracted twice with ethyl acetate, and the extracts were washed with water, followed by brine, dried over Na2SO4, filtered, and concentrated to dryness. The residue was recrystallized (EtOH/water), giving tiny tan needles (1.66 g, 55%): mp 262-264° C.; NMR (d6-acetone) δ 5.40 (br s, 4H), 7.04 (s, 2H); 13C NMR (d6-acetone) δ 103.8, 117.1, 117.4, 139.4; FAB-MS obsd 158.0591, calcd 158.0592 (C6H6N4).

Provenance & Evidence