O-Methylisourea sulfate

Application

O-methylisourea hydrogen sulfate is an amino salt that can be used as an intermediate for 5-fluorouracil. It can be used as an organic synthesis intermediate and a pharmaceutical intermediate, and is mainly used in laboratory research and development processes and chemical and pharmaceutical synthesis processes.

Chemical Properties

White or off-white solid

Synthesis

Preparation of Example 39: Synthesis of 1.3-dimethoxycarbonyl-O-methylisourea Procedure: 1. MeOH-H2SO4 solution was prepared by slowly adding sulfuric acid (112.7 g, 0.97 mol) to pre-cooled methanol (150 mL). 2. In another flask, cyanamide (50 g, 1.19 mol) was dissolved in methanol (100 mL) and cooled to about 5° C. in an ice water bath and cooled to about 5 °C. 3. The MeOH-H2SO4 solution was slowly added dropwise to the methanol solution of cyanamide while maintaining the reaction temperature at no more than 10 °C for 2 h. 4. After the dropwise addition was completed, the reaction mixture was continued to be stirred at the same temperature for 1 h. 5. At the end of the reaction, the solvent was removed by concentration in vacuum to afford O-methylisourea hydrogensulfate as a thick, syrupy product, assuming a yield of 1.5 mmol. syrupy product, assuming quantitative yield, which was used directly in the subsequent reaction.

Purification Methods

Recrystallise the salt from MeOH/Et2O (327g of salt dissolved in 1L of MeOH and 2.5L of Et2O is added) [Fearing & Fox J Am Chem Soc 76 4382 1954 ]. The picrate has m 192o [Odo et al. J Org Chem 23 1319 1958]. [Beilstein 3 IV 143.]

References

[1] Patent: US2004/254181, 2004, A1. Location in patent: Page 19