Diisopropylethylamine → 4-{2-[5-Methyl-4-(6-methylcarbamoyl-benzo[b]thiophen-2-yl)-pyrimidin-2-ylamino]-ethyl}-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of 2-(2-chloro-5-methylpyrimidin-4-yl)-benzo[b]thiophene-6-carboxylic acid methylamide (400 mg, 1.20 mmol), 4-(2-aminoethyl)-piperidine-1-carboxylic acid tert-butyl ester (688 mg, 3.01 mmol) and diisopropylethylamine (467 mg, 3.61 mmol) in 1,4-dioxane (4 mL) is heated at 95° C. under nitrogen for 3 days. At room temperature the mixture is concentrated and the crude product is chromatographed on silica gel, eluting with EtOAc in dichloromethane 0-35%, to give 4-{2-[5-methyl-4-(6-methylcarbamoyl-benzo[b]thiophen-2-yl)-pyrimidin-2-ylamino]-ethyl}-piperidine-1-carboxylic acid tert-butyl ester as a solid (264 mg, 43% yield). The intermediate is subjected to deprotection by dissolving this material (264 mg, 0.518 mmol) in MeOH (12 mL) and bubbling anhydrous HCl gas for 5 minutes. The hot, yellow solution is allowed to sit at room temperature for 2 hours, then concentrated to give the title compound as a yellow solid (246 mg, 98% yield). ES+(m/z) 410 [M(free base)+H].

Provenance & Evidence