Triethylamine → 3-bromo-1-phenylpyrrole-2,5-dione

To N-phenylmaleimide (2 g, 11.50 mmol) in chloroform (15 mL) was added bromine (0.65 mL, 12.70 mmol) dropwise in chloroform (5 mL). The reaction mixture was refluxed for 1 hour, and then allowed to cool to room temperature. The precipitate was filtered off and washed with chloroform (50 mL). This solid (2.70 g, 8.10 mmol) was dissolved in tetrahydrofuran (50 mL) and to this was added dropwise dropwise a solution of triethylamine (1.2 mL, 8.9 mmol) in tetrahydrofuran (10 mL) at 0° C. and the mixture was stirred for 2 hours. The mixture was allowed to warm to room temperature and solvent removed in vacuo. The residue was dissolved in ethyl acetate and washed with H2O (50 mL) brine (50 mL) and dried (Na2SO4). Solvent was removed in vacuo to afford the desired compound as a pale yellow solid (1.80 g, 7.14 mmol) in 62% yield. Data matched literature: Sahoo et al., Synthesis, 2003, 346

1. temperatureThe reaction mixture was refluxed for 1 hour
2. filtrationThe precipitate was filtered off
3. washwashed with chloroform (50 mL)
4. temperatureto warm to room temperature
5. customsolvent removed in vacuo
6. dissolutionThe residue was dissolved in ethyl acetate
7. washwashed with H2O (50 mL) brine (50 mL)
8. dry with materialdried (Na2SO4)
9. customSolvent was removed in vacuo

ORD record

ord-a37e90b8306d4ab681eabc3d64f827b6

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09295729B2