反应详情

21.1 g (0.1 mol) of cyanomethyl p-toluenesulphonate are added in portions to a solution of 0.01 mol of sodium methylate in 100 ml of methanol at 0° to 5° C. The mixture is allowed to come to 20° C., 5.9 g (0.11 mol) of ammonium chloride are added at this temperature and the mixture is stirred at room temperature for 4 hours. 6 g (0.125 mol) of methylmercaptan are then passed in at 10° C., a solution of 0.11 mol sodium methylate in 20 ml of methanol is added dropwise at the same temperature, and the mixture is stirred first at 0° to 5° C. for 1 hour and then without cooling for 2 hours. A further 0.22 mol of sodium methylate in 40 ml of methanol and then 13 g (0.1 mol) of methyl 2-methylacetoacetate are added to the reaction mixture at room temperature, and the mixture is subsequently stirred at room temperature for a further 18 hours. The solvent is then distilled off in vacuo, the residue is dissolved in 100 ml of water and the solution is brought to pH 4 with concentrated hydrochloric acid at 10° to 20° C. The product which has precipitated is filtered off with suction and rinsed with 20 ml of cold water. 12.8 g (70% of theory) of 2-methylthiomethyl-4-hydroxy-5,6-dimethylpyrimidine are obtained in this manner in the form of a beige powder of melting point 166° C.

1. customto come to 20° C.
2. customare then passed in at 10° C.
3. stirringthe mixture is stirred first at 0° to 5° C. for 1 hour
4. temperaturewithout cooling for 2 hours
5. stirringthe mixture is subsequently stirred at room temperature for a further 18 hours
6. distillationThe solvent is then distilled off in vacuo
7. dissolutionthe residue is dissolved in 100 ml of water
8. customis brought to pH 4 with concentrated hydrochloric acid at 10° to 20° C
9. customThe product which has precipitated
10. filtrationis filtered off with suction
11. washrinsed with 20 ml of cold water