Diethyl Ether → HCID 44128466, compound

Participants

Reaction Steps

An aqueous solution of NaNO2 (84 mg, 1.2 mmol) was added to a cooled (0° C.) solution of (3-methyl-[1,2,4]oxadiazol-5-yl)-acetic acid hydrazide (1.02 mmol) in a 1:1 mixture of CH2Cl2:1M HCl (1.5 mL). The reaction mixture was stirred at this temperature for 5 minutes before being poured onto crushed ice. The crude azide was extracted with CH2Cl2 and then dried (MgSO4), filtered and concentrated in vacuo. Toluene (1.5 mL) was added to the crude residue and the resultant mixture heated to 80° C. for 1 hour whereupon it was cooled and concentrated in vacuo to give a crude orange residue corresponding to 5-isocyanatomethyl-3-methyl-[1,2,4]oxadiazole (quantitative yield assumed) (1H NMR (400 MHz, CDCl3) δ ppm: 4.56 (2H, s), 2.36 (3H, s). IR (μmax, cm−1): 2260.7 (s, N═C═O), 1593.3 (m), 1494.9 (m), 1435.1 (w), 1325.1 (m)) which was then diluted in DMSO (1.5 mL) and added to a solution of 5-diazoimidazole-4-carboxamide (355 mg, 2.58 mmol) in 3.5 mL DMSO. The reaction mixture was stirred at room temperature for 10 minutes before the addition of sufficient ice water to cause precipitation of the crude product which was collected by vacuum filtration and washed with EtOH (1 reaction volume and then Et2O (1 reaction volume) to give the title compound as a yellow solid (56% yield). 1H NMR (400 MHz, d6-DMSO) δ ppm: 8.92 (1H, s), 7.88 (1H, s), 7.74 (1H, s), 5.89 (2H, s), 2.34 (3H, s).

Provenance & Evidence