Hydrochloric Acid → N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-amino-dibenzo[b,d]furan-1-carboxamide

Participants

Reaction Conditions

Reaction Steps

Fourth, N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-aminodibenzo[b,d]furan-1-carboxamide was prepared by reacting N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-nitro-dibenzo[b,d]furan-1-carboxamide (prepared using the procedure of Example 4) with sodium borohydride in methanol and palladium on carbon (50% wet with water) catalyst. In particular, to a 100 mL 3-neck round bottom flask were added N-(3,5-dichloropyrid-4-yl)-4-difluoromethoxy-8-nitro-dibenzo[b,d]furan-1-carboxamide (0.468 g, 1 mmol), methanol (15.0 mL), and 10% Pd—C (50% wet, 0.012 g). The reaction mixture was cooled to 5-10° C. and treated with sodium borohydride (0.127 g, 4 mmol) in four portions. The reaction mixture was acidified with conc. HCl to pH˜6, filtered and the Pd-C catalyst was washed with MeOH (˜10 ml). The combined filtrate was concentrated to a residue and slurried in excess water. The solid was filtered, washed with water (75 mL) and dried in a vacuum oven (65° C.) overnight. The dried product appeared as a yellow solid (0.310 g, 70.7%). Purity 79.57% by HPLC.

Provenance & Evidence