Ammonia → 3-Amino-4-n-butoxy-3-cyclobutene-1,2-dione

Participants

Reaction Steps

Ammonia gas was bubbled into a solution of dibutyl squarate (22.6 g, 100 mmol) in ether (500 mL) contained in a 1 L three-necked, round-bottomed flask equipped with a mechanical stirrer and an acidic scrubber. Precipitation of product ceased after 3 hours, so the reaction was halted and the ether solution was filtered. The solid residue was washed with ether and set aside. The filtrate was allowed to stand at room temperature for a further 3 hours, after which time more solid was observed to have been precipitated. This solid was collected by filtration, washed with ether, and combined with the material set aside previously. Drying in vacuo afforded the product as a white solid (15.7 g, 92.9% yield). The structure of this compound was confirmed by mass spectroscopy and by 1H and 13C NMR spectroscopy.

Provenance & Evidence