The pharmaceuticals thiobarbituric acid and sulfathiazole are prepared using thiourea. This reaction was important as a precursor to sulfathiazole, one of the first sulfa drugs. Sulfathiazole exists in various forms (polymorphs). The sulfa drug Sulfathiazole was one of the results of these research activities. Sulfathiazole is an organosulfur compound used as a short-acting sulfa drug.