| Abstract: Treatment of 2-substituted benzoic acids (2-isopropylbenzoic acid and salicylic acid) with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) mediated by PPh3 at room temperature produced two 1,4-disubstituted 2,3-dicyano-5,6-dichlorobenzenes (2 and 3) in good yields. Heating a chloroform solution of 2 and 3 to the reflux temperature in the presence of phenylamine generated amide derivatives 4 and 5, respectively. All the target compounds were fully characterized by elemental analysis, MSand 1H NMRspectrometry, and the structures of compounds 2 and 3 were further confirmed by single-crystal determination. 1,4-Bis(2-isopropylbenzoate)-2,3-dicyano-5,6-dichlorobenzene (2) crystallizes in monoclinic space group P21/c with cell parameters: a=1.2875(3) nm, b=1.5186(2) nm, c=1.5726(3) nm, β=122.23(3)°, V=2.6010(1) nm3, Dc=1.331 g·cm-3, Z=4, F(000)=1080, R1=0.0572, wR2=0.1260. 1,4-Bis(2-hydroxybenzoate)-2,3-dicyano-5,6-dichlorobenzene (3) crystallizes in triclinic space group P1 with cell parameters: a=0.87776(16) nm, b=1.13111(15) nm, c=1.18639(17) nm, α=69.290 (2)°, β=89.409 (3)°, γ=67.878 (2)°, V=1.0104(3) nm3, Dc=1.542 g·cm-3, Z=2, F(000)=476, R1=0.0383, wR2=0.0931. Strong π-π stacking interactions and intermolecular hydrogen bonds of the structures (2 and 3) stabilized the two intermediates. CCDC: 921957, 2; 935976, 3. |
