Reaction #2028882

Reaction equation

aldehyde

4-[3-formyl-5-phenyl-1H-pyrazol-1-yl]benzenesulfonamide

ethyl cyanoacetate

ammonium acetate

acetic acid

→

desired product

Yield 66.0%

Ethyl 3-[1-[4-(aminosulfonyl)phenyl]-5-phenyl-1H-pyrazol-3-yl]-2-cyano-2-propenoate

Yield 66.0%

Solvents

benzene

Conditions

Workup

1. 1
   TemperatureThe solution was heated
2. 2
   Temperatureat reflux for 18 hours
3. 3
   Temperaturecooled
4. 4
   Otherpartitioned between water and ethyl acetate
5. 5
   WashThe organic solution was washed with a saturated aqueous sodium bicarbonate solution, water and brine
6. 6
   OtherThe organic solution was dried
7. 7
   Concentrationconcentrated
8. 8
   OtherThe residue was chromatographed on silica (40% hexane in ethyl acetate)

Procedure

To a solution of the aldehyde from Step 1 (1.2 g, 3.6 mmol) in benzene (18 mL) was added ethyl cyanoacetate (0.38 mL, 3.6 mmol), ammonium acetate (50 mg, 0.7 mmol) and glacial acetic acid (0.17 mL, 2.8 mmol). The solution was heated at reflux for 18 hours, cooled, and partitioned between water and ethyl acetate. The organic solution was washed with a saturated aqueous sodium bicarbonate solution, water and brine. The organic solution was dried and concentrated. The residue was chromatographed on silica (40% hexane in ethyl acetate) to give the desired product (1.0 g, 66%): Anal. calc'd for C21H18N4O4S: C, 59.82; H, 4.30; N, 13.22. Found: C, 59.70; H, 4.29; N, 13.26.

Source