Phenol → HCID 66686295, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(3,5-dibromo-2-oxo-2H-pyrazin-1-yl)-4-methyl-benzoic acid, methyl ester (Example 1b, 204 mg), phenol (206 mg), N,N-diisopropylethylamine (0.3 mL) and tetrahydrofuran (1 mL) was heated within a microwave for 60 minutes at 140° C. before being cooled to room temperature. The mixture was transferred to a mixture of palladium on carbon (10%, 38 mg) and tetrahydrofuran (1 mL). 1,4-Cyclohexadiene (1 mL) was added and the mixture was heated under atmosphere of nitrogen within a microwave for 10 minutes at 90° C. before being cooled to room temperature. The mixture was filtered and concentrated. The residue was treated with tetrahydrofuran (10 mL), water (2 mL) and lithium hydroxide (193 mg). The mixture was stirred for 2 h, diluted with ethyl acetate, washed with 2M hydrochloric acid and water. The organic phase was dried (Na2SO4) and concentrated. The solid was washed with small amount of diethyl ether and treated with dichloromethane (3 mL) then N,N-dimethylformamide (1 drop) and oxalyl chloride (0.05 mL) were added. The mixture was stirred till solid disappeared and the solution of acid chloride was transferred to a solution of cyclopropylamine (0.3 mL) in dichloromethane (5 mL). The resulting mixture was stirred for 30 min. then diluted with ethyl acetate (50 mL). The mixture was washed with 2M hydrochloric acid and twice with water. The organic phase was dried (Na2SO4) and concentrated in vacuo. Purification by preparative HPLC (Gemini column, 0.1% ammonia:acetonitrile eluent) afforded the title compound as a solid (70 mg).

Provenance & Evidence