Cesium carbonate → 8-Methoxy-5-(thiophen-2-yl)-[1,2,4]triazolo[4,3-a]pyrazine

Temperature

100 °C

A 50 mL round bottom flask was charged with 5-bromo-8-methoxy-[1,2,4]triazolo[4,3-a]pyrazine (0.25 g, 1.1 mmol), thiophen-2-ylboronic acid (280 mg, 2.2 mmol), Pd(PPh3)4 (190 mg, 0.16 mmol), Cs2CO3 (530 mg, 1.6 mmol), 1,4-dioxane (11 mL) and water (4 mL). The resulting mixture was heated under N2 at 100° C. overnight. Work-up: the reaction mixture was filtered. The filter cake was washed with EtOAc (10 mL) and the filtrate was extracted with more EtOAc (10 mL×3). The combined organic solutions were washed with brine, dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel with a 1:50 methanol/dichloromethane, to afford 0.25 g (99%) of the product as a yellow solid. MS m/z: 233 (M+H+).

1. filtrationthe reaction mixture was filtered
2. washThe filter cake was washed with EtOAc (10 mL)
3. extractionthe filtrate was extracted with more EtOAc (10 mL×3)
4. washThe combined organic solutions were washed with brine
5. dry with materialdried over anhydrous Na2SO4
6. concentrationconcentrated in vacuo
7. customThe residue was purified by flash column chromatography on silica gel with a 1:50 methanol/dichloromethane

ORD record

ord-253db3cef78643d1bb071e927acd7f4c

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08569300B2