Yield:311-77-3 94.5%

Reaction Conditions:

Stage #1: dimethyl aminewith sulfuric acid in water at 20; for 3 h;
Stage #2: CYANAMID in water at 25;Temperature;

Steps:

2 Example 2

Laboratory analytical purchase of the trimethylamine solution to form the quality content 33% aqueous solution of the spare.
In a 500 ml three-necked round bottom flask, input preparation of 33% dimethylamine aqueous solution 170.5g (1.25 mol). Start the stirring. Cooled to 20 °C or less. Around 1h add dropwise 98% concentrated sulfuric acid 60.0g (0.6 mol). Dropwise addition completed. Continue maintainin temperature and react for 2h; then heat up to 25 °C, for 4 - 5h uniform speed add dropwise 50% cyanamide 84.0g (1.0 mol). Completion of adding dropwise. Maintain temperature and react for 1h; cooling to - 5 - 0 °C and maintain 1h, filtration, and dried to obtain the 176.9g N,N-dimethylguanidine sulfate, content 99.0%, yield 94.5% (single cyanamide idea).

References:

CN106278955,2017,A Location in patent:Paragraph 0025; 0026; 0027; 0031-0036