反应详情

To a solution of 217 mg (0.447 mmol) of 14 in 50 mL of dry benzene, was added 3.2 mL (3.20 mmol) of 1 M BBr3 in methylene chloride. The resulting mixture was refluxed for 5 hours. Additional BBr3 (1.3 mL, 1.3 mmol) was then added to the reaction mixture, and the mixture was refluxed for an additional 5 hours. After cooling the reaction mixture to room temperature, methanol was added to destroy the excess BBr3, and the solvents were removed in vacuo. The yellowish-red solid residue was redissolved in 5 mL methanol and 75 mL of water added to the solution resulting in precipitation of a greenish-yellow solid. Filtration, and washing the solids with water, and then washing with diethyl ether gave pure 18: 137 mg (71%) yield; dec pt >285° C.; TLC (n-butanol/acetic acid/water [5:2:3]), Rf =0.42; IR (KBr pellet) 3328, 3024, 1649, 1669, 1419, 1271, 1245, 1225, 1038, 800 cm-1 ; 1H NMR (dimethyl-d6 sulfoxide) δ4.45 (4H, s, methylenes); mass spectrum, (EI solids probe), m/z 430, 432, and 434 (P+ for the 79Br, 79Br; 79Br, 81Br; 81Br, 81Br combinations, respectively, at an intensity ratio of 1:2:1). Anal. Calcd for C12H8Br2N4O4.0.5H2O: C, 32.68; H, 2.05; N, 12.70. Found: C, 32.84; H, 1.89; N, 12.10.

1. temperatureThe resulting mixture was refluxed for 5 hours
2. temperaturethe mixture was refluxed for an additional 5 hours
3. customto destroy the excess BBr3
4. customthe solvents were removed in vacuo
5. dissolutionThe yellowish-red solid residue was redissolved in 5 mL methanol
6. addition75 mL of water added to the solution
7. customresulting in precipitation of a greenish-yellow solid
8. filtrationFiltration
9. washwashing the solids with water
10. washwashing with diethyl ether
11. customgave pure 18
12. custom137 mg (71%) yield