Triphenylphosphine → 1-(2,2-Dimethyl-4-oxotetralin-1-yl)-5-imidazolecarboxylic acid methyl ester

HRID 2089494Notes

Reaction equation

HRID 2089494 reaction equation
O[CH:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5](=[O:12])[CH2:4][C:3]1([CH3:14])[CH3:13].[NH:15]1[CH:19]=[C:18]([C:20]([O:22][CH3:23])=[O:21])[N:17]=[CH:16]1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OC)=O)=NC(OC)=O>C1COCC1>[CH3:23][O:22][C:20]([C:18]1[N:17]([CH:2]2[C:11]3[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=3)[C:5](=[O:12])[CH2:4][C:3]2([CH3:14])[CH3:13])[CH:16]=[N:15][CH:19]=1)=[O:21]

Participants

6

Reactant 4

HCID 11776TriphenylphosphineHCID 351621Azodicarboxylic acid dimethyl esterHCID 135275814-hydroxy-3,3-dimethyl-3,4-dihydro-2H-naphthalen-1-oneHCID 178418785HCID 178418785, compound

Product 1

HCID 249960101-(2,2-Dimethyl-4-oxotetralin-1-yl)-5-imidazolecarboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 4-hydroxy-3,3-dimethyl-3,4-dihydro-2H-naphthalen-1-one (2.87 g, 13.88 mmol) and methyl 4-imidazolecarboxylate (CAS#17325-26-7, 1.25 g, 9.72 mmol) in THF (80 mL) at 0° C. is added triphenylphosphine (3.68 g, 13.88 mmol) and dimethyl azodicarboxylate (40% in toluene, 5.14 mL, 13.88 mmol) and the cooling bath is removed. After 15 hours, the mixture is concentrated and the resulting residue is dissolved in ethyl acetate (250 mL) and is extracted five times with 1M aqueous HCl (40 mL portions). The acidic aqueous phases are cooled to 0° C. and the pH is adjusted to ca. 12 with 4M aqueous NaOH at 0° C. The aqueous phase is then extracted three times with dichloromethane. The combined organic layers are dried over MgSO4 and filtered, and concentrated. The resulting residue is purified by silica gel flash chromatography (dichloromethane-methanol, 49:1) to give 3-(2,2-dimethyl-4-oxo-1,2,3,4-tetrahydro-naphthalen-1-yl)-3H-imidazole-4-carboxylic acid methyl ester; MS: (ESI) m/z 299.0 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 0.97 (s, 3 H), 1.15 (s, 3 H), 2.63 (d, J=16.8 Hz, 1 H), 2.74 (d, J=16.8 Hz, 1 H), 3.93 (s, 3 H), 6.79 (s, 1 H), 7.02 (d, J=7.6 Hz, 1 H), 7.35 (s, 1 H), 7.47 (t, J=7.6 Hz, 1 H), 7.55 (td, J=7.6, 1.5 Hz, 1 H), 7.86 (s, 1 H), 8.13 (dd, J=7.6, 1.5 Hz, 1 H);

Workup

  1. customthe cooling bath is removed
  2. concentrationthe mixture is concentrated
  3. dissolutionthe resulting residue is dissolved in ethyl acetate (250 mL)
  4. extractionis extracted five times with 1M aqueous HCl (40 mL portions)
  5. customat 0° C
  6. extractionThe aqueous phase is then extracted three times with dichloromethane
  7. dry with materialThe combined organic layers are dried over MgSO4
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe resulting residue is purified by silica gel flash chromatography (dichloromethane-methanol, 49:1)

Sources & evidence

ORD record
ord-f07e16d2b4044fd49a5db35b9248dd43
Source dataset
uspto-grants-2013_05
Patent number
US08436035B2

Reaction notes

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