反应详情

A mixture of 1,2-phenylenediamine (0.1 mole, 10.8 g) and 1,4-dibromo-2,3-butanedione (0.1 mole, 24.4 g) was refluxed in benzene (200 mL) using a Dean-Stark trap for one hour. The reaction mixture was then evaporated to dryness in vacuo and the residue flash chromatographed on silica gel (15:1). Elution with 15% hexane/chloroform afforded 29.38 g of 2,3-bis(bromomethyl)quinoxaline, m.p. 150°-151° C.; 1H NMR (CDCl3, 200 MHz): δ4.92 (s, 4H, CH2), 7.8 (m, 2H, ArH), 8.05 (m, 2H, ArH).

1. customfor one hour
2. customThe reaction mixture was then evaporated to dryness in vacuo
3. customthe residue flash chromatographed on silica gel (15:1)
4. washElution with 15% hexane/chloroform