Trimethylsilyldiazomethane → Methyl 2-amino-4,6-dimethoxybenzoate

HRID 631347Notes

Reaction equation

HRID 631347 reaction equation
[NH2:1][C:2]1[CH:10]=[C:9]([O:11][CH3:12])[CH:8]=[C:7]([O:13][CH3:14])[C:3]=1[C:4]([OH:6])=[O:5].[CH3:15][Si](C=[N+]=[N-])(C)C>CO.C1COCC1.C(OCC)C>[NH2:1][C:2]1[CH:10]=[C:9]([O:11][CH3:12])[CH:8]=[C:7]([O:13][CH3:14])[C:3]=1[C:4]([O:6][CH3:15])=[O:5]

Participants

6

Reactant 2

HCID 167693TrimethylsilyldiazomethaneHCID 116584562-Amino-4,6-dimethoxybenzoic acid

Product 1

HCID 11550253Methyl 2-amino-4,6-dimethoxybenzoateYield 76%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a mixture of 2-amino-4,6-dimethoxybenzoic acid (7.888 g, 40 mmol) in MeOH (40 mL) and THF (40 mL) at room temperature was dropped 2.0 M solution of (trimethylsilyl)diazomethane in diethyl ether. The mixture was stirred at room temperature overnight. After the solvent was evaporated under reduced pressure, water and EtOAc was added to the residue. The organic layer was separated, dried (MgSO4) and concentrated under reduced pressure. The crude product was purified by silica gel chromatography with 20-40% EtOAc/hexane as eluants to afford methyl 2-amino-4,6-dimethoxybenzoate as a solid (6.462 g, 76%). 1H NMR (300 MHz, CDCl3) δ 5.83 (d, 1H), 5.78 (d, 1H), 5.53 (br, 2H), 3.86 (s, 3H), 3.80 (s, 3H), 3.77 (s, 3H); LC-MS (ESI) m/z 212 (M+H)+.

Workup

  1. customAfter the solvent was evaporated under reduced pressure, water and EtOAc
  2. additionwas added to the residue
  3. customThe organic layer was separated
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated under reduced pressure
  6. customThe crude product was purified by silica gel chromatography with 20-40% EtOAc/hexane as eluants

Sources & evidence

ORD record
ord-051799271f8548fbbc1383a847663278
Source dataset
uspto-grants-2016_04
Patent number
US09320739B2

Reaction notes

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