反应详情

0.87 mL (1384 mmol) methyl iodide diluted in 2 mL methanol was added dropwise to 2.00 g (8.65 mmol) N-(6-bromopyridin-2-yl)thiourea suspended in 30 mL methanol, and the mixture was heated for 1.45 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 25 mL ethanol, and after addition of 2.37 mL (18.168 mmol) 2-methoxybenzylamine was heated for 3 hr under reflux, whereupon the solid completely dissolved. For workup the solvent was removed under vacuum, and the crude mixture was taken up in dichloromethane. Extraction was performed with water (2×100 mL) and with 2 N sodium hydroxide solution (1×100 mL) to liberate the iodide salt. Subsequent washing of the organic phase with water (1×100 mL), drying over magnesium sulfate, and evaporation of the solvent under vacuum resulted in a light brown-yellow oil, from which a colorless crystallizate was isolated from dichloromethane/pentane in a refrigerator at 5° C. Further fractionated crystallization in acetonitrile/water resulted in a total of 2.18 g (6.50 mmol, 75%) N-(6-bromopyridin-2-yl)-N′-(2-methoxybenzyl)guanidine.

1. temperaturethe mixture was heated for 1.45 hr
2. temperatureunder reflux
3. temperaturewas heated for 3 hr
4. temperatureunder reflux, whereupon the solid
5. dissolutioncompletely dissolved
6. customFor workup the solvent was removed under vacuum
7. extractionExtraction
8. washSubsequent washing of the organic phase with water (1×100 mL)
9. dry with materialdrying over magnesium sulfate, and evaporation of the solvent under vacuum
10. customresulted in a light brown-yellow oil, from which a colorless crystallizate
11. customcrystallization in acetonitrile/water