Urea is byproduct of converting alkyl halides to thiols via a S-alkylation of thiourea. Benzyl mercaptan can be prepared by the reaction of benzyl chloride and thiourea. Nonclassic antagonists lack the urea, thiourea, or amide groups typical of the classic TRPV1 ligands. Other hydrogen-bonded networks are derived from hydroquinone, urea, and thiourea. Polonium also forms soluble compounds with some chelating agents, such as 2,3-butanediol and thiourea. A large group of organocatalysts incorporate the urea or the thiourea moiety. Instead, alkyl halides are converted to thiols via an "S"-alkylation of thiourea. Upon cooling, the ammonium salt converts back to thiourea. Although impractical, it can be prepared by the reaction of methyl iodide with thiourea. Propylthiouracil can be prepared from ethyl 3-oxohexanoate and thiourea. Other industrial uses of thiourea include production of flame retardant resins, and vulcanization accelerators. Other ligands for octahedral coordination include PPh, PPhMe and thiourea. It can also be used as a desulfuration-fluorination reagent on thiourea derived substrates. Reaction of 4 with thiourea thus leads to formation of an aminothiazole moiety. Sulfoxylate ions can be made by decomposing thiourea dioxide in an alkaline solution.