Pyridine → Ethyl 1,2,4-thiadiazole-5-carboxylate

Temperature

25 °C

To ethyl {[(1E)-(dimethylamino)methylidene]amino}(thioxo)acetate (I78) (1.42 g, 7.54 mmol) and pyridine (1.220 mL, 15.09 mmol) dissolved in Ethanol (20 mL) was added (aminooxy)(hydroxy)sulfane dioxide (0.938 g, 8.30 mmol) dissolved in Ethanol (18 ml) and the mixture stirred at 25° C. for 48 hr. The solvents were concentrated in vacuo and the residue was dissolved in ethyl acetate (50 mL). The solution was washed with saturated sodium bicarbonate solution (25 mL), aqueous phase back extracted with ethyl acetate (25 mL) and the organic extracts were combined. The solution was washed with brine (25 mL), dried over anhydrous sodium sulfate and concentrated in vacuo to afford a crude oil. The crude oil was purified by flash chromatography (Isolera, 50 g, 0-100% ethyl acetate/iso-hexane, 15 column volumes) to afford product in 246 mg.

1. concentrationThe solvents were concentrated in vacuo
2. dissolutionthe residue was dissolved in ethyl acetate (50 mL)
3. washThe solution was washed with saturated sodium bicarbonate solution (25 mL), aqueous phase
4. extractionback extracted with ethyl acetate (25 mL)
5. washThe solution was washed with brine (25 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated in vacuo
8. customto afford a crude oil
9. customThe crude oil was purified by flash chromatography (Isolera, 50 g, 0-100% ethyl acetate/iso-hexane, 15 column volumes)
10. customto afford product in 246 mg

ORD record

ord-89b17d9be811400abffdacf7fe74650e

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08501946B2