反应详情

3-bromo-4-chloro-5-fluoro-pyridine (500 mg, 2.376 mmol), hydrazine (761.4 mg, 745.7 μL, 23.76 mmol), Na2CO3 (503.7 mg, 4.752 mmol) in cyclohexanol was heated at 100 C overnight. The reaction mixture was filtered on celite and loaded on a SCX column, washed with DCM/MeOH mixtures and was eluted with a 2M solution of NH3 in MeOH. The filtrate was concentrated in vacuo and the 3/1 mixture of 3-bromo-5-fluoro-4-hydrazinylpyridine and 3-bromo-4-chloro-5-hydrazinylpyridine was used in next step without further purification. MS (ES+) 205.9.

1. filtrationThe reaction mixture was filtered on celite and
2. washwashed with DCM/MeOH mixtures
3. washwas eluted with a 2M solution of NH3 in MeOH
4. concentrationThe filtrate was concentrated in vacuo
5. additionthe 3/1 mixture of 3-bromo-5-fluoro-4-hydrazinylpyridine and 3-bromo-4-chloro-5-hydrazinylpyridine
6. customwas used in next step without further purification