Hydrochloric Acid → 3-Amino-4-phenyl-1,2,5-thiadiazole

3-Chloro-4-phenyl-1,2,5-thiadiazole (3.19 g, 16.2 mmol) in THF (32 ml) at 0° C. was treated dropwise with a solution of lithium bis(trimethylsilyl)amide in THF (17.0 ml, 1.0 M, 17.0 mmol). After 10 min the mixture allowed to warm to ambient temperature for 1.5 hr, treated with 1N hydrochloric acid, and extracted three times into ether (total 300 ml). The combined organic phases were washed with saturated aqueous sodium bicarbonate and brine, and dried over magnesium sulfate and concentrated in vacuo. The residue was dissolved in methanol (50 ml) and triethylamine (0.5 ml) was heated to reflux for 15 hr and again concentrated in vacuo. Flash chromatography on silica gel (ethyl acetate/hexanes) yielded 3-amino-4-phenyl-1,2,5-thiadiazole (1.96 g, 68%) as a colorless solid.

1. extractionextracted three times into ether (total 300 ml)
2. washThe combined organic phases were washed with saturated aqueous sodium bicarbonate and brine
3. dry with materialdried over magnesium sulfate
4. concentrationconcentrated in vacuo
5. dissolutionThe residue was dissolved in methanol (50 ml)
6. temperaturetriethylamine (0.5 ml) was heated
7. temperatureto reflux for 15 hr
8. concentrationagain concentrated in vacuo

ORD record

ord-42c7b7fd672340159e3dec8441e339a7

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08110568B2