反应详情

2-Amino-4-chloro-5-nitrophenol (20.03 g, 0.133 mol), anhydrous potassium carbonate (20.0 g, 0.14 5mol) and tetrabutylammonium iodide (0.025 g, 0.068 mmol) were added to a dry 500 mL and covered with a septum. Freshly distilled and dry DMF (90 mL) was added, followed by benzyl bromide (13.8 mL, 0.116 mol) and the reaction was stirred overnight at room temperature under N2. The solution was then concentrated by removing the DMF on the Kugelrohr apparatus (50° C., 0.25 mm Hg). The oily residue was dissolved in CHCl3, suction filtered to remove the excess potassium carbonate and washed with water. The filtrate was concentrated on a rotovap until a yellow solid remained. The crude product was first purified using a chloroform silica gel column. The product, 2-benzyloxy-5-chloro-4-nitroaniline, was collected from the first few fractions. The product was then purified on a silica gel column using 20% ethyl acetate/hexane eluent. The product was collected, concentrated on a rotovap and dried under high-vacuum to give 2-benzyloxy-5-chloro-4-nitroaniline as a yellow solid (13.44 g, 48.34 mmol, 56%). Mp 98-103° C. TLC (20% ethyl acetate/hexane) Rf=0.38; 500 MHz 1H-NMR (CDCl3) 7.68 (s, 1H), 7.42 (m, 5H), 6.72 (s, 1H), 5.13 (s, 2H), 4.52 (s br, 2H); IR (nujol) 3469, 3378, 3355, 1613, 1567, 1522, 1483, 1464, 1377, 1217, 1126; EI-MS m/z (relative intensity) 278 (M+, 11). Accurate mass for C13H11N2O3Cl: calcd. 278.0458, obsd. 278.0468.

1. distillationFreshly distilled
2. additiondry DMF (90 mL) was added
3. concentrationThe solution was then concentrated
4. customby removing the DMF on the Kugelrohr apparatus (50° C., 0.25 mm Hg)
5. dissolutionThe oily residue was dissolved in CHCl3
6. filtrationsuction filtered
7. customto remove the excess potassium carbonate
8. washwashed with water
9. concentrationThe filtrate was concentrated on a rotovap until a yellow solid
10. customThe crude product was first purified
11. customThe product, 2-benzyloxy-5-chloro-4-nitroaniline, was collected from the first few fractions
12. customThe product was then purified on a silica gel column
13. customThe product was collected
14. concentrationconcentrated on a rotovap
15. customdried under high-vacuum