Urea → Thiazolo[4,5-d]pyrimidine-5,7-diol

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 4-aminothiazole-5-carboxylate 40 (WO 2006/096338; WO 2005/049613) and urea is heated at 190° C. for 2 hours. The hot reaction mixture is poured onto sodium hydroxide solution and any insoluble material is removed by filtration. The mixture is acidified (HCl, 2N) to yield thiazolo[4,5-d]pyrimidine-5,7(4H,6H)-dione 41 (Baker et al (1970) Jour. of the Chem. Soc. 18:2478-84; U.S. Pat. No. 3,277,093; Childress and McKee (1951) J. Am. Chem. Soc. 73:3862-64; Erlenmeyer and Furger (1943) Helv. Chem. Acta 26:366-68) as a white precipitate, which was collected by filtration and air dried.

Provenance & Evidence