反应详情

温度

70 °C

To a suspension of 3-methyl-5-(4-nitro-phenyl)-[1,2,4]thiadiazole (422 mg, 1.9 mmol, CAS 800408-77-9, Wilkins, D. J.; Bradley, P. A. Science of Synthesis (2004), 13, 277-295.) in ethanol (19 mL) was added under stirring tin(II)chloride (1.86 g, 9.54 mmol) and heated to 70° C. for 4 hours. The mixture was poured on cold aqueous saturated sodium hydrogen carbonate solution. The suspension was stirred for 30 minutes and the solid was filtered off, washed with water. The residue was heated two to three times with tetrahydrofurane and filtered. The aqueous layer was extracted twice with ethyl acetate. The combined organic layers were dried over sodium sulfate and the solvent was evaporated under reduced pressure. The residue was stirred with diethyl ether and the solid was filtered off and washed with diethyl ether/heptane to yield the title compound as a yellow solid (355 mg, 97%). MS ISP (m/e): 192.2 (100) [(M+H)+]. 1H NMR (DMSO-D6, 300 MHz): δ (ppm)=7.64 (d, 2H), 6.63 (d, 3H), 6.01 (BR s, 2H, NH2), 2.54 (s, 3H).

1. additionwas added under stirring tin(II)chloride (1.86 g, 9.54 mmol)
2. filtrationthe solid was filtered off
3. washwashed with water
4. temperatureThe residue was heated two to three times with tetrahydrofurane
5. filtrationfiltered
6. extractionThe aqueous layer was extracted twice with ethyl acetate
7. dry with materialThe combined organic layers were dried over sodium sulfate
8. customthe solvent was evaporated under reduced pressure
9. stirringThe residue was stirred with diethyl ether
10. filtrationthe solid was filtered off
11. washwashed with diethyl ether/heptane