4-Toluenesulfonyl chloride → 6-Methylpyridazine-3-carbonitrile

To a stirring solution of 3-methylpyridazine (11 g, 118 mmol) in dichloromethane (200 mL) was added AlCl3 (0.05 g) followed by trimethylsilylcyanide (21 g, 211 mmol). After 20 min, a solution of p-toluenesulfonyl chloride (38 g, 201 mmol) in dichloromethane (50 mL) was added via addition funnel and the solution continued to stir overnight. The next morning, the solvent was removed in vacuo and the residue was suspended in ethanol with stirring for 15 min and then filtered to give a white solid. The solid was dissolved in tetrahydrofuran (200 mL) and to this stirring solution was added 1,8-diazabicyclo[5.4.0]undec-7-ene (16 mL, 105 mmol). After 1 h, the solvent was removed in vacuo and the residue was partitioned between hexanes and saturated aqueous NH4Cl. The phases were separated and the aqueous phase was basified with solid Na2CO3, then extracted three times with ethyl acetate. The combined ethyl acetate phases were dried (MgSO4), filtered and concentrated in vacuo to give 9 g (64%) of white solid.

1. customThe next morning, the solvent was removed in vacuo
2. stirringwith stirring for 15 min
3. filtrationfiltered
4. customto give a white solid
5. waitAfter 1 h
6. customthe solvent was removed in vacuo
7. customthe residue was partitioned between hexanes and saturated aqueous NH4Cl
8. customThe phases were separated
9. extractionextracted three times with ethyl acetate
10. dry with materialThe combined ethyl acetate phases were dried (MgSO4)
11. filtrationfiltered
12. concentrationconcentrated in vacuo

ORD record

ord-7e3590ad24c1453da52a2934999d7762

Source dataset

uspto-grants-1998_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05710130