反应详情

0.37 mL (5.89 mmol) methyl iodide diluted in 2 mL methanol was added dropwise to 1.032 g (4.46 mmol) N-(6-bromopyridin-2-yl)thiourea suspended in 30 mL methanol, and the mixture was heated for 2 hr under reflux. The reaction mixture was in solution. The methylated intermediate product, consisting of methyl N-(6-bromopyridin-2-yl)imidothiocarbamate hydroiodide (ESI-MS [M+H+]=247.85 calculated for C7H8BrN3S=246), was freed of solvent under vacuum. The intermediate product was then suspended in 30 mL ethanol, and 1.122 g (6.442 mmol) 2,6-dimethoxybenzylamine was added, whereupon the solid completely dissolved. The mixture was then heated for 2.25 hr under reflux. The colorless solid which precipitated was suctioned off and washed with ethanol. 1.197 g N-(6-bromopyridin-2-yl)-N′-(2,6-dimethoxybenzyl)guanidine was obtained as crude product. Repeated crystallization from acetonitrile/water resulted in the isolation of 1.311 g (3.589 mmol, 81%) N-(6-bromopyridin-2-yl)-N-(2,6-dimethoxybenzyl)guanidine, which was also used for the subsequent reaction and derivatizations.

1. temperaturethe mixture was heated for 2 hr
2. temperatureunder reflux
3. dissolutioncompletely dissolved
4. temperatureThe mixture was then heated for 2.25 hr
5. temperatureunder reflux
6. customThe colorless solid which precipitated
7. washwashed with ethanol