Nitromethane → Beta-Nitrostyrene

HRID 1021191Notes

Reaction equation

HRID 1021191 reaction equation
COCO[C:5]1[C:14](C)=[C:13](C)[C:12]2OC(C)(C)[CH2:9][CH2:8][C:7]=2[C:6]=1C=O.C([O-])(=O)C.[NH4+].[N+:26](C)([O-:28])=[O:27]>CCOC(C)=O>[N+:26]([CH:9]=[CH:8][C:7]1[CH:12]=[CH:13][CH:14]=[CH:5][CH:6]=1)([O-:28])=[O:27]

Participants

5

Reactant 3

HCID 6375NitromethaneHCID 517165Ammonium AcetateHCID 86653769HCID 86653769, compound

Product 1

HCID 7626Beta-Nitrostyrene

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

6-(Methoxymethoxy)-2,2,7,8-tetramethylchroman-5-carbaldehyde (500 mg, 1.7 mmol) and ammonium acetate (157 mg, 1.7 mmol) were taken up in nitromethane (11.6 mL) and the mixture was warmed to 80° C. for 1.5 hrs. After this time, the reaction was judged to be complete and the mixture was diluted in EtOAc (75 mL), washed once with brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Silica gel chromatography (gradient elution 0→15% EtOAc/Heptane) afforded the yellow solid nitrostyrene intermediate (500 mg). 1H NMR (CDCl3, 400 MHz) 8.30 (d, 2H), 7.80 (d, 2H), 4.82 (s, 2H), 3.76 (s, 3H), 2.78 (t, 2H), 2.20 (s, 3H), 2.12 (s, 3H), 1.80 (t, 2H), 1.26 (s, 6H) ppm. The intermediate compound was dissolved in 5 mL THF and added dropwise over 30 min to a stirring suspension of LiAlH4 (400 mg, 10 mmol) in 3 mL THF at 0° C. After addition was complete, the mixture was stirred at 50° C. After 5 hr total, excess reagent was quenched by addition of 3 g sodium sulfate dodecylhydrate. The resulting suspension was stirred for 30 min, during which time the grey color turned to white. Subsequently, the suspension was filtered, and the filtrate concentrated in vacuo to provide 2-(6-(methoxymethoxy)-2,2,7,8-tetramethylchroman-5-yl)ethanamine as a colorless oil, 450 mg. 1H NMR (CD3OD, 400 MHz) 4.84 (s, 2H), 3.60 (s, 3H), 2.80 (m, 4H), 2.70 (t, 2H), 2.14 (s, 3H), 2.06 (s, 3H), 1.78 (t, 2H), 1.22 (s, 3H), 1.20 (s, 3H) ppm.

Workup

  1. washwashed once with brine
  2. dry with materialdried over anhydrous sodium sulfate
  3. filtrationfiltered
  4. concentrationconcentrated in vacuo
  5. washSilica gel chromatography (gradient elution 0→15% EtOAc/Heptane)

Sources & evidence

ORD record
ord-a3958621a8f04d35beae93aa9f58ccb6
Source dataset
uspto-grants-2014_05
Patent number
US08716527B2

Reaction notes

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