Uses
O-methylisourea can be used in the synthesis of heterocyclic compounds; it is a guanylation reagent and a selective alkylating agent.
Application
Methyl Carbamimidate is preparation of Ph (3-methoxy-1,2,4-thiadiazol-5-yl)carbamate from O-methylisourea hydrochloride.
Preparation
O-methylisourea hydrochloride is prepared in 69-80% yield by adding 1.15 equiv HCl(g) with ice cooling to cyanamide dissolved in excess anhydrous methanol. The free base is obtained from the salt using powdered KOH in a water-ether mixture or with sodium methoxide in methanol. The monoacetate salt can be prepared from the free base with 1 equiv of HOAc. Drying: vacuum desiccator over P2O5.
storage
Salts are hygroscopic and should be stored in a desiccator even for brief periods. Heating O-methylisourea to decomposition can liberate toxic fumes of NOx. Use in a fume hood.
