Benzoyl chloride → 4-Methylbenzophenone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The following experimental procedure is representative of the reactions set forth below in Table II. The organocalcium reagent (2.72 mmol) was prepared from p-chlorotoluene (344 mg, 2.72 mmol) and highly reactive calcium (3.15 mmol) as described above. CuCN.2LiBr in THF (10 mL) was added to the organocalcium reagent via a cannula at -35° C. The CuCN.2LiBr can be prepared from CuCN and approximately two equivalents of LiBr in THF, as outlined in P. Knochel et al., J. Org. Chem., 53, 2390 (1989), which is incorporated herein by reference. The reaction mixture was stirred at -35° C. for 30 minutes. Benzoyl chloride (950 mg, 6.76 mmol) was added to the mixture via a disposable syringe at -35° C. and the resulting mixture was gradually warmed to room temperature. Saturated aqueous NH4Cl solution (20 mL) was then added to the reaction mixture at room temperature for the purpose of neutralizing the reaction mixture. The reaction mixture was then filtered through a small pad of Celite™ filter agent and was washed with Et2O (50 mL). The aqueous layer was extracted with Et2O (2×30 mL). The combined organic phases were washed with H2O (3×15 mL) and dried over anhydrous MgSO4. Removal of solvent and flash-column chromatography on silica gel (100 g, 230-400 mesh, eluted sequentially with 20:1 hexanes/EtOAc, 15:1 hexanes/EtOAc, and 10:1 hexanes/EtOAc) yielded (4-methylphenyl)phenylmethanone (458 mg, 86% yield): IR (neat) 3058, 3027, 2921, 1658, 1606, 1446, 1317, 1278, 1178, 937, 924, 835, 787, 730, 700 cm-1 ; 1H NMR (200 MHz, CDCl3) δ 7.24-7.82 (m, 9 H), 2.43 (s, 3 H); 13C NMR (50 MHz, CDCl3) δ 196.4, 143.2, 137.9, 134.8, 132.1, 130.3, 129.9 128.9, 128.2, 21.6.

Herkunft & Nachweise