反应详情

A solution of 20 g (0.13 mole) of 2-methyl-6-nitroaniline in 22.9 ml of concentrated aqueous hydrochloric acid, 200 ml of tetrahydrofuran, and 350 ml of methanol was hydrogenated at room temperature using 25 psi. of hydrogen gas over 2.0 g of 5% palladium on carbon. The mixture was filtered and the filtrate was concentrated in vacuo. The residue was dissolved in 150 ml of ethanol and neutralized with 17.2 g (0.26 mole) of potassium hydroxide dissolved in 30 ml of water. Potassium ethylxanthate (23 g, 0.155 mole) was added and the mixture was heated at reflux for 18 hours. Upon cooling, a solid was collected, washed with water, and air dried to yield 6.2 g of 2-mercapto-4-methylbenzimidazole, as confirmed by the nmr and infrared spectra. The title compound (1.5 g) was prepared by the method of Example 84 using 1.6 g of 2-mercapto-4-methylbenzimidazole instead of 2-mercaptobenzimidazole. Structure assignment was supported by the nmr and infrared spectra and by elemental analysis. Analysis. Calc'd. for C14H14N4S*½H2O: C, 60.19; H, 5.01;N, 20.05; S, 11.45. Found: C, 60.49; H, 5.03; N, 20.41; S, 11.76.

1. customwas hydrogenated at room temperature
2. filtrationThe mixture was filtered
3. concentrationthe filtrate was concentrated in vacuo
4. temperaturethe mixture was heated
5. temperatureat reflux for 18 hours
6. temperatureUpon cooling
7. customa solid was collected
8. washwashed with water, and air
9. customdried