反应详情

Benzocyclobutenone (1.20 g) was added slowly to concentrated sulfuric acid (5 mL) at 0° C. with vigorous stirring. The mixture of concentrated sulfuric acid (1.0 mL) and nitric acid (70%, 1.05 g) was added at such a rate that the solution temperature remained at 10° C. After the completion of addition of nitrating solution, the reaction mixture was then poured into icey water (30 mL). The resulting mixture was filtered. The filtrate was neutralized with sodium carbonate powders and the water was then evaporated under vacuum. The residue was then extracted with methylene chloride (3×50 mL). After removal of methylene chloride, the pure product (3-nitrobenzocyclobutenone) was isolated from the residue by chromatography on silica gel: 55 mg; IR (KBr) 1349, 1525, 1772 cm-1 ; 1H NMR (200 MHz, CDCl3) 4.42 (s, 2H), 7.68 (m, 2H), 8.31 (m, 1H); MS (EI, m/e, relative intensity %) 164 (M+. +H, 2.5), 135 (M+. -CO, 10.3), 89 (135 -.NO2, 38).

1. additionwas added at such a rate that the solution temperature
2. customremained at 10° C
3. additionAfter the completion of addition of nitrating solution
4. filtrationThe resulting mixture was filtered
5. customthe water was then evaporated under vacuum
6. extractionThe residue was then extracted with methylene chloride (3×50 mL)
7. customAfter removal of methylene chloride