Acetohydrazide → 6-Chloro-3-methyl-(1,2,4)triazolo(4,3-b)pyridazine

To a stirred solution of 1.0 g (6.7 mmol) of 3,6-dichloropyridazine in 5 mL of butanol was added 500 mg (6.7 mmol) of acetic hydrazide and the resulting solution was stirred under nitrogen at reflux for 24 h. The reaction mixture was then cooled to ambient temperature, filtered, and the resulting precipitate washed with ethyl acetate and methanol. The combined filtrate and washings were concentrated and dissolved in 250 mL of 10:1 chloroform/methanol then washed with saturated aqueous brine (2×100 mL). The organic phase was then dried over magnesium sulfate, filtered, and evaporated in vacuo to yield a yellow solid. The crude material was purified by flash chromatography on a Biotage Horizon® system (silica gel, 0 to 80% ethyl acetate/hexanes gradient) to give the title compound as a brown crystalline solid. LC/MS 169.0 (M+1).

1. temperatureat reflux for 24 h
2. filtrationfiltered
3. washthe resulting precipitate washed with ethyl acetate and methanol
4. concentrationThe combined filtrate and washings were concentrated
5. dissolutiondissolved in 250 mL of 10:1 chloroform/methanol
6. washthen washed with saturated aqueous brine (2×100 mL)
7. dry with materialThe organic phase was then dried over magnesium sulfate
8. filtrationfiltered
9. customevaporated in vacuo
10. customto yield a yellow solid
11. customThe crude material was purified by flash chromatography on a Biotage Horizon® system (silica gel, 0 to 80% ethyl acetate/hexanes gradient)

ORDレコード

ord-4e9aaeeaf9014e7cb8f96aeb837a7ebd

出典データセット

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07884104B2