反应详情

The mixture of the above obtained methyl [1-(2-chlorophenyl)-5-hydroxy-1H-pyrazol-3-yl]acetate (Compound of Formula (IV), 0.60 g), was suspended in acetonitrile (5 mL) and glacial acetic acid (14 mg, 0.1 eq.) and 2-chloro-1,1,1-triethoxyethane (1.5 g) under nitrogen, was heated at 70° C. for 45-60 minutes. The resulting red solution was concentrated in vacuo to afford a red syrup that was washed with cyclohexane and then dried in vacuo. Due to its relative instability, no further purification of methyl [4-(chloroacetyl)-1-(2-chlorophenyl)-5-hydroxy-1H-pyrazol-3-yl]acetate was conducted (0.77 g, quantitative yield). MS (ESL): 344.3; MS (ESI−): 342.2.

1. additionThe mixture of the
2. concentrationThe resulting red solution was concentrated in vacuo
3. customto afford a red syrup that
4. washwas washed with cyclohexane
5. customdried in vacuo
6. customDue to its relative instability, no further purification of methyl [4-(chloroacetyl)-1-(2-chlorophenyl)-5-hydroxy-1H-pyrazol-3-yl]acetate