Diisopropylethylamine → HCID 178522684, compound

Participants

Reaction Steps

To a solution of 0.20 g (0.41 mmol) 2,5-dichloro-4-[3-(4-cyclopropyl-3,4-dihydro-2H-quinoxaline-1-carbonyl)-pyridin-4-yloxy]-benzoic acid (Example 29, intermediate) in 2 mL N,N-dimethylformamide were added 0.165 g (0.43 mmol) 0-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU, commercially available, CAS RN 148893-10-1) and 0.21 mL (1.24 mmol) N,N-diisopropylethylamine. To the yellow solution 0.037 g (0.43 mmol) 5-amino-1H-tetrazole (commercially available, CAS RN 4418-61-5) was added and the solution was stirred at room temperature for 3.25 hours. Then the solution was heated to 60° C. and stirred at this temperature for 88 hours. After filtration over a syringe micro filter, the reaction mixture was purified by preparative HPLC (Phenomenex Gemini column) with a gradient of acetonitrile:water (containing 0.05% formic acid) (10:90 to 98:2) to give the desired compound as a light brown solid (0.051 g, 22%). MS (ESI): m/z=551.11 [M+H]+.

Provenance & Evidence