HCID 57202434, compound → HCID 57111740, compound

Participants

Reaction Conditions

Reaction Steps

A solution of (3S-trans)-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-yl)-N'-(2,3-dihydro-2-methyl-1H-isoindol-5-yl)urea (1.0 g, 1.8 mmol, compound of example 19) in acetic acid (4 mL) was treated with zinc dust (0.35 g, 5.4 mmol) under argon and heated at 80° C. for 16 hours. Additional amount (0.4 g) of zinc dust was added and the reaction mixture was heated for eight hours. It was cooled to room temperature, diluted with chloroform (100 mL) and filtered. The solvent was evaporated in vacuo and the residue was acidified with 10% hydrochloric acid (10 mL). It was then extracted with ethyl acetate and the organic extract was discarded. The acid layer was made basic (pH~11) with 10% sodium hydroxide solution, saturated with salt and extracted with chloroform (3×100 mL). The aqueous layer was filtered and the filtrate was concentrated in vacuo. The residue was diluted with 40% aqueous isopropanol. The precipitate was faltered and dried to yield the title compound (0.2 g) as a colorless solid, m.p. 215°-217° C. [αD ]25 =-13.9° (c=0.42, DMF).

Provenance & Evidence