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

HRID 1917790Notes

Reaction equation

HRID 1917790 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-7f08ca43e8484cdf8b1dd79ea68cbb1c
Source dataset
uspto-grants-2013_12
Patent number
US08618289B2

Reaction notes

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