N-bromobutanimide → HCID 89739428, compound

To a solution of 5-methyl-4H-pyrrolo[2,3-d]thiazole (2.5 g, 18.09 mmol) in acetic acid (50 mL) was added 1-bromopyrrolidine-2,5-dione (3 g, 18.10 mmol) slowly below 0° C., and then warm to the ambient temperature and allowed to stir for 2 hours at room temperature. The reaction mixture was concentrated, and acetic acid was removed under reduced pressure. The pH was adjusted to around 7 by progressively adding saturated sodium bicarbonate below 0° C., extracted with acetic ester (50 mL×3). The combined organic phase was dried by anhydrous sodium sulphate, and then filtered. The filtrate was concentrated and purified by column chromatograph on silica gel eluted with (petrol ether/acetic ester 25:1→15:1→10:1) to give the title compound (2.5 g, 64%) as an yellow solid. LCMS (M+H+) m/z: calc'd. 215.94. found 219.2.

1. concentrationThe reaction mixture was concentrated
2. customacetic acid was removed under reduced pressure
3. customwas adjusted to around 7 by progressively adding saturated sodium bicarbonate below 0° C.
4. extractionextracted with acetic ester (50 mL×3)
5. dry with materialThe combined organic phase was dried by anhydrous sodium sulphate
6. filtrationfiltered
7. concentrationThe filtrate was concentrated
8. custompurified by column chromatograph on silica gel
9. washeluted with (petrol ether/acetic ester 25:1→15:1→10:1)

ORD record

ord-460b167ee5b742c581da9a339765bf52

Source dataset

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09371331B2