Methyl 2-amino-3-hydroxy-5-methylbenzoate → Methyl 2-amino-6-methylbenzoxazole-4-carboxylate

HRID 249921Notes

Reaction equation

HRID 249921 reaction equation
[N:1]1(C(N2C=CN=C2)N)C=CN=[CH:2]1.[NH2:13][C:14]1[C:23]([OH:24])=[CH:22][C:21]([CH3:25])=[CH:20][C:15]=1[C:16]([O:18][CH3:19])=[O:17]>C1COCC1>[NH2:1][C:2]1[O:24][C:23]2[C:14](=[C:15]([C:16]([O:18][CH3:19])=[O:17])[CH:20]=[C:21]([CH3:25])[CH:22]=2)[N:13]=1

Participants

4

Reactant 2

HCID 21755136Methyl 2-amino-3-hydroxy-5-methylbenzoateHCID 66874404di(1H-imidazole-1-yl)methanamine

Product 1

HCID 66874433Methyl 2-amino-6-methylbenzoxazole-4-carboxylateYield 45%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of di (1H-imidazole-1-yl)methanamine (1.56 g, 9.67 mmol) in THF (30 mL) was added methyl 2-amino-3-hydroxy-5-methylbenzoate (1.40 g, 7.73 mmol) at room temperature and the resulting reaction mixture was heated at reflux for 6 h. The reaction mixture was cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in CH2Cl2 (100 mL), treated with saturated aqueous ammonium chloride (25 mL), and then extracted with CH2Cl2 (2×100 mL). The combined organic phase was washed with brine (2×100 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure to afford a yellow solid. The solid was triturated from CH3OH to afford methyl 2-amino-6-methylbenzoxazole-4-carboxylate (0.717 g, 45%). 1H NMR and MS consistent.

Workup

  1. customthe resulting reaction mixture
  2. temperaturewas heated
  3. temperatureat reflux for 6 h
  4. concentrationconcentrated under reduced pressure
  5. dissolutionThe residue was dissolved in CH2Cl2 (100 mL)
  6. additiontreated with saturated aqueous ammonium chloride (25 mL)
  7. extractionextracted with CH2Cl2 (2×100 mL)
  8. washThe combined organic phase was washed with brine (2×100 mL)
  9. dry with materialdried (Na2SO4)
  10. filtrationfiltered
  11. concentrationconcentrated under reduced pressure
  12. customto afford a yellow solid
  13. customThe solid was triturated from CH3OH

Sources & evidence

ORD record
ord-1e57ef9aef8b42c0acadced7b7b9d7e4
Source dataset
uspto-grants-2011_01
Patent number
US07863271B2

Reaction notes

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