Derquantel is a semi-synthetic paraherquamide analogue prepared by removal of the 2-oxo group in a four-step sequence of N-protection, reduction, N-deprotection and a final reduction. Derquantel is a potent nematocide and was the first paraherquamide to be successfully commercialised in combination with avermectin. Derquantel, like other paraherquamides, induces a flaccid paralysis in nematodes thought to be due to inhibition of nicotinic acetylcholine receptors acting as an antagonist of acetylcholine.