Sodium Hydroxide → HCID 56970895, compound

Participants

Reaction Conditions

Reaction Steps

In a 100 mL round bottomed flask was placed stereo isomeric mixture of 4-(4-chlorophenyl)-2-pyridin-4-yl-5,6-dihydro-1-benzothiophen-7(4H)-one oxime prepared above and then was added polyphosphoric acid (11 g, 46 mmol) and the mixture was stirred for 6 h at 130° C. During this period, the mixture was occasionally mixed by hand. The mixture was allowed to cool to ambient temperature and then was added crushed ice (ca 20 ml) while the reaction mixture is hot. The mixture was stirred for 30 min at rt. A dark brown suspension was obtained, which was basicified by the addition of 5N NaOH (30 mL, pH ca 12). The mixture was extracted with a 1:1 mixture of CH2Cl2 and THF (30 mL×3). The combined organic phase was dried over anhydrous MgSO4. Insoluble materials were removed by filtration and the filtrate was concentrated under reduced pressure to obtain title compound (230 mg; 68%) as a yellowish off-white powder, which was only one isomer.

Provenance & Evidence