Reaction #792219

Reaction equation

4-amino-5-methyl-2-(pyridin-3-yl)-2,4-dihydro-3H-1,2,4-triazol-3-one

sodium nitrite

sodium hydroxide

→

5-Methyl-2-(pyridin-3-yl)-2,4-dihydro-3H-1,2,4-triazol-3-one

Solvents

water

hydrochloric acid

water

Conditions

Workup

1. 1
   ExtractionThe mixture was extracted repeatedly with ethyl acetate
2. 2
   Dryingthe combined organic phases were dried with sodium sulfate
3. 3
   Concentrationconcentrated
4. 4
   OtherThis gave 253 mg of 5-methyl-2-(pyridin-3-yl)-2,4-dihydro-3H-1,2,4-triazol-3-one in the form of a white solid (content LC-MS: 100%) which was used for the next reaction

Procedure

750 mg (3.923 mmol) of 4-amino-5-methyl-2-(pyridin-3-yl)-2,4-dihydro-3H-1,2,4-triazol-3-one were dissolved in a mixture of 9 ml of water and 3 ml of concentrated hydrochloric acid. At 5° C., a solution of 314 mg (4.55 mmol) of sodium nitrite in 1 ml of water was then added dropwise. The reaction mixture was then allowed to warm to room temperature and stirred for another 1 hour. The reaction mixture was neutralized using 30% strength aqueous sodium hydroxide solution and a few drops of an aqueous sodium bisulfite solution were added such that the test with potassium iodide/starch paper is negative. The mixture was extracted repeatedly with ethyl acetate, and the combined organic phases were dried with sodium sulfate and concentrated. This gave 253 mg of 5-methyl-2-(pyridin-3-yl)-2,4-dihydro-3H-1,2,4-triazol-3-one in the form of a white solid (content LC-MS: 100%) which was used for the next reaction.

Source