Table 2: ¹H NMR data for G4; chemical shifts in ppm relative to TMS (1%) at room temperature in CDCl₃

Compound	Aromatic	O-CH3
G4	8.26 (d, J = 8 Hz; 2H, Ar-H)	3.64 (s, 6H, OCH3)
-	8.16 (d, J = 8 Hz; 2H, Ar-H)	-
-	7.45 (t, J = 8 Hz; 2H, Ar-H)	-
-	7.09 (t, J = 8 Hz; 2H, Ar-H)	-
-	6.56 (d, J = 4 Hz; 2H, Ar-H)	-
-	6.23 (t, J = 4 Hz; 1H, Ar-H)	-