Cesium carbonate → US9777003, Example 69

Participants

Reaction Conditions

Reaction Steps

1-Benzyl-5-chloro-2-(1,3-thiazol-5-yl)-1H-pyrrolo[3,2-b]pyridine (67 mg, 0.20 mmol, from Step 1), di-tert-butyl hydrazine-1,2-dicarboxylate (72 mg, 0.31 mmol) and Cs2CO3 (100 mg, 0.31 mmol) were combined in toluene (7.2 mL) and dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine-(2′-aminobiphenyl-2-yl)(chloro)palladium (1:1) (16 mg, 0.020 mmol) was added. The mixture was degassed by a stream of nitrogen through the solution for 10 minutes. The reaction was stirred at 110° C. overnight, then was cooled, diluted with DCM, filtered and concentrated. Flash chromatography, eluting with a gradient from 0-50% EtOAc in hexanes afforded intermediate di-tert-butyl 1-[1-benzyl-2-(1,3-thiazol-5-yl)-1H-pyrrolo[3,2-b]pyridin-5-yl]hydrazine-1,2-dicarboxylate. This intermediate was heated in the microwave as a solution in AcOH (3.0 mL) to 180° C. for 6 minutes. AcOH was removed in vacuo, the residue was reconstituted, and the product was concentrated and purified via preparative HPLC-MS (C18 eluting with a gradient of MeCN and H2O containing 0.15% NH4OH). Yield: (12.5 mg, 18%).

Provenance & Evidence