Thiophosgene → 2-Isothiocyanato-3,5-dimethylpyrazine

Thiophosgene (1.59 mL, 20.9 mmol) was added dropwise to a stirred mixture of 3,5-dimethylpyrazin-2-amine (1.98 g, 16.1 mmol) in tetrahydrofuran (20 mL) and saturated aqueous sodium hydrogen carbonate (20 mL) at 0° C., and the mixture was stirred at 0° C. for 1 hr. The mixture was diluted with saturated aqueous sodium hydrogen carbonate, and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 10-50% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the title compound as a brown solid (866 mg, 5.24 mmol, 33%).

1. extractionextracted with ethyl acetate
2. washThe combined organic layer was washed with brine
3. dry with materialdried over anhydrous magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by flash column chromatography on silica gel eluting with a 10-50% ethyl acetate/n-hexane gradient mixture
7. concentrationThe filtrate was concentrated in vacuo

ORD record

ord-5f77cd73ea6b4045a7e1a10d44d4f967

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08901141B2