反应详情

Sulfuric acid (112.7 g, 0.97 mol) was added carefully to a cooled CH3OH (150 mL) solution. In a separate flask, cyanamide (50 g, 1.19 mol) was dissolved in methanol (100 mL) and chilled to ca 5° C. in ice-water. Over 2 h, the MeOH—H2SO4 solution was added such that the reaction temperature did not rise above 10° C. After the last addition, the solution was stirred for an additional 1 h and then concentrated in vacuo to give O-methylisourea hydrogen sulfate as a thick-viscous syrup with an assumed quantitative yield which was used directly in the next step.

1. customdid not rise above 10° C
2. additionAfter the last addition
3. concentrationconcentrated in vacuo