Diisopropylethylamine → [4-(4-Bromo-2,5-dichloro-phenoxy)-pyridin-3-yl]-(4-cyclopropyl-3,4-dihydro-2H-quinoxalin-1-yl)-methanone

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Reaction Steps

To a suspension of 5.0 g (13.77 mmol) 4-(4-bromo-2,5-dichloro-phenoxy)-nicotinic acid in 30 mL N,N-dimethylformamide were added 5.50 g (14.46 mmol) O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU, commercially available, CAS RN 148893-10-1) and 7.03 mL (41.32 mmol) N,N-diisopropylethylamine. To this brown solution was added 2.52 g (14.46 mmol) 1-cyclopropyl-1,2,3,4-tetrahydro-quinoxaline (Example 8, intermediate a), the resulting clear brown solution was stirred at room temperature for 17 hours and then poured on 120 mL water and 120 mL ethyl acetate. The resulting mixture was filtered, the filter cake was thoroughly washed with water and a very small amount of ethyl acetate to give after drying 6.55 g (92%) of the title compound as a brown solid. MS (ESI): m/z=520.1 [M+H]+.

Provenance & Evidence