2-Nitroethanol → 6-Bromo-3-nitro-chroman

HRID 1986620ノート

反応式

HRID 1986620 の反応式
[Br:1][C:2]1[CH:9]=[C:6]([CH:7]=O)[C:5]([OH:10])=[CH:4][CH:3]=1.[Cl-].[CH2:12]([NH2+:16]CCCC)[CH2:13]CC.[N+:21]([CH2:24][CH2:25][OH:26])([O-:23])=[O:22].[BH3-]C#N.[Na+]>C(OCCCCC)(=O)C.O>[Br:1][C:2]1[CH:9]=[C:6]2[C:5](=[CH:4][CH:3]=1)[O:10][CH2:13][CH:12]([NH2:16])[CH2:7]2.[Br:1][C:2]1[CH:9]=[C:6]2[C:5](=[CH:4][CH:3]=1)[O:26][CH2:25][CH:24]([N+:21]([O-:23])=[O:22])[CH2:7]2

参加物

8

反応物 4

HCID 122522-NitroethanolHCID 728635-BromosalicylaldehydeHCID 517667N-butylbutan-1-amine hydrochlorideHCID 5003444Sodium cyanoborohydride

生成物 2

HCID 162444326-Bromochroman-3-amineHCID 221377596-Bromo-3-nitro-chroman収率 74.1%

試薬・触媒・溶媒 2

HCID 962Water溶媒HCID 12348Amyl Acetate溶媒

実験手順

6-Bromo-chroman-3-ylamine was prepared according to the literature procedure described by Andersson, B. R. et al. WO9012795. Thus, a mixture of 5-bromosalicylaldehyde (9.5 g, 47 mmol), di-n-butylammonium chloride (3.8 g, 23 mmol), and 2-nitroethanol (6.8 g, 75 mmol) in amyl acetate (60 mL) was heated at reflux for 3 hours with a Dean-Stark apparatus under nitrogen atmosphere. The solvent was removed in vacuo and the product was dissolved in CH2Cl2 (280 mL) followed by the addition of NaCNBH3 (9.6 g, 150 mmol). The mixture was stirred for 30 minutes and water (100 mL) was added to quench the reaction. The organic layer was separated and the aqueous layer was extracted with CH2Cl2 (50 mL×3). The combined organic layers were washed with brine, dried (Na2SO4), and concentrated in vacuo. The crude product was chromatographed on silica gel by eluting with 1:1 hexane/CH2Cl2 to give 4.4 g (40%) of pure 6-bromo-3-nitro-chroman as a light yellow solid. 1H NMR (300 MHz, CDCl3): δ 7.18 (m, 2H), 6.68 (d, J=8.4 Hz, 1H), 4.88 (m, 1H), 4.62 (m, 1H), 4.32 (m, 1H), 4.47 (m, 1H), 3.28 (dd, J=17.4, 6.0 Hz, 1H).

後処理

  1. temperaturewas heated
  2. temperatureat reflux for 3 hours with a Dean-Stark apparatus under nitrogen atmosphere
  3. customThe solvent was removed in vacuo
  4. dissolutionthe product was dissolved in CH2Cl2 (280 mL)
  5. customto quench
  6. customthe reaction
  7. customThe organic layer was separated
  8. extractionthe aqueous layer was extracted with CH2Cl2 (50 mL×3)
  9. washThe combined organic layers were washed with brine
  10. dry with materialdried (Na2SO4)
  11. concentrationconcentrated in vacuo
  12. customThe crude product was chromatographed on silica gel
  13. washby eluting with 1:1 hexane/CH2Cl2

出典と根拠

ORDレコード
ord-1a1b221234b84a6da6d11bdcd5ae93eb
出典データセット
uspto-grants-2009_06
特許番号
US07550467B2

反応ノート

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