Diisopropylethylamine → HCID 178493464, compound

Participants

Reaction Steps

A mixture of 8-(2,6-dichloro-3,5-dimethoxy-phenyl)-quinoxaline-5-carboxylic acid (300 mg, 0.791 mmol) (Step 179.1), 2-amino-4-diethoxymethyl-imidazole-1-carboxylic acid tert-butyl ester (226 mg, 0.791 mmol) (Step 179.8), TBTU (305 mg, 0.949 mmol, 1.2 equiv) and DIEA (409 mg, 3.17 mmol, 4 equiv) in DMF (6 mL) was stirred for 48 h at rt. After further addition of 2-amino-4-diethoxymethyl-imidazole-1-carboxylic acid tert-butyl ester (80 mg, 0.280 mmol) (Step 179.8), the reaction mixture was stirred for additional 72 h at rt, diluted with EtOAc/H2O and extracted with EtOAc. The organic phase was washed with H2O and brine, dried (Na2SO4), filtered and concentrated. The residue was purified by silica gel column chromatography (EtOAc/Hex, 1:1) to afford 470 ring of a mixture of products. Part of this mixture (280 mg) was dissolved in acetone (3 mL) and H2O (2 mL) and treated with PPTS (10.9 mg). The reaction mixture was stirred for 7 h at rt, heated to 50° C., stirred for 20 h, allowed to cool to rt and diluted with EtOAc/H2O. The resulting yellow precipitate was collected by vacuum filtration and dried to provide 128 mg of the title compound: ES-MS: 472 [M+H]+; tR=4.16 min (System 1).

Provenance & Evidence