Sulfuric Acid → Ethyl 1-amino-3,3-dimethyl-3,4-dihydronaphthalene-2-carboxylate

HRID 1886895Notes

Reaction equation

HRID 1886895 reaction equation
OS(O)(=O)=O.[C:6]([CH:8]([C:14]([CH3:23])([CH3:22])[CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[C:9]([O:11][CH2:12][CH3:13])=[O:10])#[N:7]>[NH4+].[OH-]>[NH2:7][C:6]1[C:17]2[C:16](=[CH:21][CH:20]=[CH:19][CH:18]=2)[CH2:15][C:14]([CH3:22])([CH3:23])[C:8]=1[C:9]([O:11][CH2:12][CH3:13])=[O:10]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 236365Ethyl 2-cyano-3,3-dimethyl-4-phenylbutanoate

Product 1

HCID 15758044Ethyl 1-amino-3,3-dimethyl-3,4-dihydronaphthalene-2-carboxylateYield 36.4%

Reagents, catalysts & solvents 1

HCID 14923Ammonium HydroxideSolvent

Procedure

Concentrated H2SO4 (2.35 mL, 44.0 mmol) was added dropwise to ethyl 2-cyano-3,3-dimethyl-4-phenylbutanoate (1.08 g, 4.4 mmol) at 0° C. to give an orange solution. The reaction was allowed to warm to room temperature and was stirred for 24 h. Ice water (10 mL) was added to the deep red reaction to give an opaque yellow mixture. The reaction was basified with NH4OH (20 mL) and extracted with ether (3×10 mL). The organic extracts were washed with water and brine, dried over Na2SO4, and concentrated under reduced pressure to give bright yellow oil. Purified by flash column chromatography (20% ethyl acetate in hexanes, Rf=0.30) afforded the title compound as bright yellow crystalline solid (392.4 mg, 36.4% yield). 1H NMR (500 MHz, CDCl3) δ 7.39 (d, J=7.5 Hz, 1H), 7.31-7.28 (m, 2H), 7.18 (d, J=7.2 Hz, 1H), 6.33 (s, 2H), 4.26 (q, J=7.1 Hz, 2H), 2.65 (s, 2H), 1.34 (t, J=7.1 Hz, 3H), 1.20 (s, 6H).

Workup

  1. customto give an orange solution
  2. customto give an opaque yellow mixture
  3. extractionextracted with ether (3×10 mL)
  4. washThe organic extracts were washed with water and brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated under reduced pressure
  7. customto give bright yellow oil
  8. customPurified by flash column chromatography (20% ethyl acetate in hexanes, Rf=0.30)

Sources & evidence

ORD record
ord-ff0f9fa44d2e4b2ca13b36eace675812
Source dataset
uspto-grants-2013_08
Patent number
US08501722B2

Reaction notes

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