反応 #54531
ord-7556692fc255402b9f7f0dc2724696b2
反応方程式
試薬
溶媒
反応条件
後処理
- 1その他at -50° to -70°
- 2濃縮The mixture was concentrated in vacuo at 30° to a small volume, ice-water
- 3workup.ADDITIONwas added
- 4抽出solid NaCl and extracted with ethyl acetate (5×100 ml)
- 5乾燥The extract was dried (MgSO4)
- 6その他evaporated
- 7その他to give 0.657 g
- 8抽出The aqueous was extracted again with CHCl3 (4×100 ml.)
- 9その他to give 0.561 g
- 10抽出The last extraction
- 11その他to give 0.3 g
- 12その他The three crops were crystallized from benzene
- 13その他to give 0.548 g
実験手順
A solution of boron tribromide (7.52 g.; 0.03 mole) in 20 ml. of CH2Cl2 was added to a solution of trans-N-[2-(dimethylamino)cyclohexyl]-3-methoxy-4-nitrobenzamide (1.93 g.; 0.006 mole) in 50 ml. of CH2Cl3 keeping the temperature at -50° to -70°. It was allowed to warm to room temperature and stirred overnight. The mixture was concentrated in vacuo at 30° to a small volume, ice-water was added followed by solid NaHCO3 to pH 8, then solid NaCl and extracted with ethyl acetate (5×100 ml). The extract was dried (MgSO4) and evaporated to give 0.657 g. of solid. The aqueous was extracted again with CHCl3 (4×100 ml.) to give 0.561 g. of solid. The last extraction was repeated to give 0.3 g. of solid. The three crops were crystallized from benzene to give 0.548 g. of orange prisms, m.p. 139°- 140°. The analytical sample melted at 138°-140° (efferv.). NMR analysis showed this product to contain ca. 30% of benzene. This impure titled product was heated at 120°-125° for 17 hours in a sublimation tube (the m.p. changed to 198°-199.5°) and was then sublimed at 170°-175° for 18 hours. The sublimate, orange prisms, melted at 202°-203.5°. uv λmax 238 nm nm (ε 11,600); 278 (7,900); 358 (2,350); 422 (2,850). ir NH/=CH/N+H/OH 3220, 3180, 3020, ~2900 broad, C=O 1655; C=C 1600; amide II/NO2 /C=C 1580, 1485, 1335; C--N/C--O 1260, 1240, 1220, 1155, 995. NMR in CDCl3 +d6DMSO (100 MHz) showed absence of benzene. Mass spectrum M+ 307.