THIOUREA PRACT
Thiourea PRACT is a white crystalline solid, both naturally occurring and synthetic, that is soluble in water, ammonium thiocyanate solution and ethanol. In the past, it was used as a photographic toning agent, a component of hair preparations and a dry cleaning agent.
Thiourea is used as an auxiliary agent in diazo paper, light-sensitive photocopy paper and almost all other types of copy paper. It is also used to tone silver-gelatin photographic prints.
Dissolve 500 mg 6-chloro-A in 5ml ethanol, add 1.5 equivalents of thiourea and reflux for 1 hour. After the reaction cools down i remove the filtrate and concentrate the flow-though.
Thiourea was the drug initially used to treat Graves' disease; however, it had considerable toxicity. Second-generation drugs and derivatives such as propylthiouracil and methylthiouracil, methimazole, and carbimazole have less toxicity.