2. 2-Thio-orotic acid is desulfurized by the action of chromic acid, or with hydrogen peroxide in alkaline solution to give orotic acid quantita- tively. The acid is not desulfurized by the action of chloroacetic acid. 3. 2-Thio-4-hydroxymethyluracil is desulfurized and converted quanti- tatively into 4-hydroxymethyluracil by digestion with chloroacetic acid in aqueous solution. 4. 2-Thio-orotic acid and 2- thio-4-hydroxymethyluracil interact with alkyl halides in alkaline ...