The reaction of p-chlorobenzoic acid (I) with SOCl2 gives p-chlorobenzoyl chloride (II), which is esterified with 4-fluorophenol (III) affording 4-fluorophenyl-4-chlorobenzoate (IV). The isomerization of (IV) with AlCl3 yields 4-chloro-2'-hydroxy-5'-fluorobenzophenone (V), which is condensed with 4-aminobutyric acid (VI) by means of sodium methoxide in ethanol giving 4-[[alpha-(p-chlorophenyl)-5-fluoro-2-hydroxybenzylidene]amino]butyric acid (VII). The reaction of (VII) with SOCl2 in THF affords the corresponding acyl chloride (VIII), which is then treated with NH3. An alternative way of converting the acid (VII) into its amide is by treatment with carbonyldiimidazole (A) and liquid NH3 in THF.

The reaction of p-chlorobenzoic acid (I) with SOCl2 gives p-chlorobenzoyl chloride (II), which is esterified with 4-fluorophenol (III) affording 4-fluorophenyl-4-chlorobenzoate (IV). The isomerization of (IV) with AlCl3 yields 4-chloro-2'-hydroxy-5'-fluorobenzophenone (V), which is condensed with 4-aminobutyric acid (VI) by means of sodium methoxide in ethanol giving 4-[[alpha-(p-chlorophenyl)-5-fluoro-2-hydroxybenzylidene]amino]butyric acid (VII). The reaction of (VII) with SOCl2 in THF affords the corresponding acyl chloride (VIII), which is then treated with NH3. An alternative way of converting the acid (VII) into its amide is by treatment with carbonyldiimidazole (A) and liquid NH3 in THF.

The reaction of p-chlorobenzoic acid (I) with SOCl2 gives p-chlorobenzoyl chloride (II), which is esterified with 4-fluorophenol (III) affording 4-fluorophenyl-4-chlorobenzoate (IV). The isomerization of (IV) with AlCl3 yields 4-chloro-2'-hydroxy-5'-fluorobenzophenone (V), which is condensed with 4-aminobutyric acid (VI) by means of sodium methoxide in ethanol giving 4-[[alpha-(p-chlorophenyl)-5-fluoro-2-hydroxybenzylidene]amino]butyric acid (VII). The reaction of (VII) with SOCl2 in THF affords the corresponding acyl chloride (VIII), which is then treated with NH3. An alternative way of converting the acid (VII) into its amide is by treatment with carbonyldiimidazole (A) and liquid NH3 in THF.

The reaction of p-chlorobenzoic acid (I) with SOCl2 gives p-chlorobenzoyl chloride (II), which is esterified with 4-fluorophenol (III) affording 4-fluorophenyl-4-chlorobenzoate (IV). The isomerization of (IV) with AlCl3 yields 4-chloro-2'-hydroxy-5'-fluorobenzophenone (V), which is condensed with 4-aminobutyric acid (VI) by means of sodium methoxide in ethanol giving 4-[[alpha-(p-chlorophenyl)-5-fluoro-2-hydroxybenzylidene]amino]butyric acid (VII). The reaction of (VII) with SOCl2 in THF affords the corresponding acyl chloride (VIII), which is then treated with NH3. An alternative way of converting the acid (VII) into its amide is by treatment with carbonyldiimidazole (A) and liquid NH3 in THF.