Cesium carbonate → tert-Butyl-3-chloro-4-{[3-(4-chlorophenyl)-4-cyclopropyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]methyl}benzoate

Participants

Reaction Conditions

Reaction Steps

An amount of 1.00 g (4.22 mmol) of 5-(4-chlorophenyl)-4-cyclopropyl-2,4-dihydro-3H-1,2,4-triazol-3-one (preparation as per WO 2007/134862 Example 36A) and 2.07 g (6.37 mmol) of caesium carbonate were suspended in 15 ml of acetone and admixed with 1.69 g (5.52 mmol) of tert-butyl-4-(bromomethyl)-3-chlorobenzoate (preparation as per WO 2003/000692, Example 4b). The mixture was stirred at 50° C. for 18 h. The suspension was diluted with water. It was extracted with twice 15 ml of ethyl acetate. The combined organic phases were dried over sodium sulphate and freed from the solvent on a rotary evaporator. Purification by flash chromatography over silica gel with elution with cyclohexane/ethyl acetate (gradient 9:1→3:2) gave 1.41 g (53% of theory) of the target compound in a purity of 74%.

Provenance & Evidence