Tetrahydrofuran → HCID 178481535, compound

Participants

Reaction Steps

Starting from 4-cyanobenzoic acid, synthesis was carried out analogously to Example 40. Only the final step differed as follows. 6.15 g of 3-{(4-cyanophenyl)-[4-(1-methyl-1H-imidazol-4-yl)phenylamino]methylene}-1-methyl-1,3-dihydroindol-2-one was dissolved in 200 mL of methanolic ammonia and THF and hydrogenated with 5 g of Raney nickel at RT and under a pressure of 50 psi. After about 10 hours, the catalyst was removed by suction filtering and the filtrate was again filtered through a glass filter, evaporated down, and the crystalline residue was filtered with diisopropyl ether suction. The crystals were suspended in 400 mL of methanol, adjusted to pH 1 with 10% ethanolic hydrochloric acid, and heated to boiling temperature. The mixture was filtered and the filtrate was evaporated down to a residual volume of about 100 mL and combined with 300 mL of ethanol. After further evaporation to approximately 100 mL residual volume, the substance crystallized out. After cooling, it was suction filtered and washed with ice-cold ethanol. Yield: 6.15 yellow crystals; melting point>300° C.; Rf value=0.32 (dichloromethane/methanol/ammonia (85:15:1)).

Provenance & Evidence