Hydrazine hydrate (1:1) → 2-(3-Aminopyridin-4-yl)-5-(trifluoromethyl)benzoxazole

HRID 1913630Notes

Reaction equation

HRID 1913630 reaction equation
[F:1][C:2]([F:30])([F:29])[C:3]1[CH:4]=[CH:5][C:6]2[O:10][C:9]([C:11]3[CH:16]=[CH:15][N:14]=[CH:13][C:12]=3[N:17]3C(=O)C4=CC=CC=C4C3=O)=[N:8][C:7]=2[CH:28]=1.O.NN>C(O)C>[NH2:17][C:12]1[CH:13]=[N:14][CH:15]=[CH:16][C:11]=1[C:9]1[O:10][C:6]2[CH:5]=[CH:4][C:3]([C:2]([F:30])([F:29])[F:1])=[CH:28][C:7]=2[N:8]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 66880022N-{4-[5-(trifluoromethyl)benzoxazole-2-yl]pyridin-3-yl}phthalimide

Product 1

HCID 668801682-(3-Aminopyridin-4-yl)-5-(trifluoromethyl)benzoxazoleYield 67.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

To a mixture of 0.41 g of N-{4-[5-(trifluoromethyl)benzoxazole-2-yl]pyridin-3-yl}phthalimide and 5 ml of ethanol, 0.3 ml of hydrazine monohydrate was added and stirred at room temperature for 1.5 hours. To the reaction mixture, ethanol was added and filtrated, and the filtrate was concentrated. The residue was diluted with ethyl acetate, and washed with water and then with a saturated sodium chloride solution. The organic layer was dried over anhydrous magnesium sulfate, and then concentrated under reduced pressure. The residue was subjected to silica gel column chromatography to give 0.19 g of 2-(3-aminopyridin-4-yl)-5-(trifluoromethyl)benzoxazole (hereinafter, referred to as “active compound 52”).

Workup

  1. additionwas added
  2. filtrationfiltrated
  3. concentrationthe filtrate was concentrated
  4. additionThe residue was diluted with ethyl acetate
  5. washwashed with water
  6. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-dc2d513995cb4ad29b4b740ddb1dba4a
Source dataset
uspto-grants-2013_12
Patent number
US08609705B2

Reaction notes

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