2-Nitroethanol → 8-Bromo-3-nitrochroman

HRID 1464698

Reaction equation

HRID 1464698 reaction equation
[Br:1][C:2]1[CH:9]=[CH:8][CH:7]=[C:4]([CH:5]=O)[C:3]=1[OH:10].[Cl-].C([NH2+]CCCC)CCC.[N+:21]([CH2:24][CH2:25]O)([O-:23])=[O:22].C([BH3-])#N>C(OC(=O)C)CC(C)C.CO.O>[Br:1][C:2]1[CH:9]=[CH:8][CH:7]=[C:4]2[C:3]=1[O:10][CH2:25][CH:24]([N+:21]([O-:23])=[O:22])[CH2:5]2

Participants

8

Reactant 4

HCID 122522-NitroethanolHCID 498716Cyano-borohydrideHCID 517667N-butylbutan-1-amine hydrochlorideHCID 109105553-Bromo-2-hydroxybenzaldehyde

Product 1

HCID 190871628-Bromo-3-nitrochromanYield 63%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 31276Isoamyl AcetateSolvent

Procedure

Commercially available 3-bromosalicylaldehyde (0.5 g; 2.5 mmol), di-n-butylammonium chloride (0.2 g; 1.2 mmol) and 2-nitroethanol (0.36 g; 4.0 mmol) were refluxed for 8 hours in i-pentylacetate with a Dean-Stark apparatus under nitrogen atmosphere. The solvent was evaporated and the product was dissolved in dichloromethane (15 ml) and cyanoborohydride (0.5 g; 8.1 mmol) in methanol (15 ml) was added. The mixture was stirred for 30 minutes at room temperature. Water was added and the mixture extracted with dichloromethane. The phase were separated and the organic layer was dried (MgSO4). The solvent was evaporated yielding 400 mg (63%) of 8-bromo-3-nitrochroman as an oil.

Workup

  1. customThe solvent was evaporated
  2. dissolutionthe product was dissolved in dichloromethane (15 ml)
  3. extractionthe mixture extracted with dichloromethane
  4. customThe phase were separated
  5. dry with materialthe organic layer was dried (MgSO4)
  6. customThe solvent was evaporated

Sources & evidence

ORD record
ord-9b0f3df3890e45cca073dab5c798eac6
Source dataset
uspto-grants-1994_04
Patent number
US05306830

Linked notes

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