3,3-Dimethylbutylamine → 5-{4-[(3,3-Dimethylbutylamino)methyl]-2-methylphenoxy}pyrazine-2-carboxamide

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Reaction Steps

Place 5-(4-formyl-2-methylphenoxy)pyrazine-2-carboxamide (Example 404, Part D) (0.200 g, 0.777 mmol), 3,3-dimethylbutylamine (0.100 g, 0.777 mmol) and 3 Å molecular sieves in a vial. Add methanol (3.8 mL), cap and stir overnight. Add NaBH4 (in excess over two portions) and stir until the gasses stop evolving. Load the reaction mixture directly onto a 5 g ISCO® pre-load column. Dry the pre-loaded column in a vacuum oven at room temperature. Purify by eluting through a 10 g ISCO® column with (2.0 M NH3 in methanol), ethyl acetate and hexanes. After concentrating, take the product up in CH2Cl2 (25 mL) and wash with 1.0 N NaOH solution (2×10 mL). Dry the organic layer over Na2SO4, filter and concentrate to give the title compound (0.110 g, 41.4%): MS ES+ 343.1 (M+H)+, base peak 242.0 (M-C6H14N)+; HPLC [YMC-Pack Pro C-18 (150×4.6 mm, S-5 microm), 0.1% TFA/acetonitrile in 0.1% TFA/water at 1.0 mL/min, 5-95% over 19 min], tR=9.7 min, 94.3% purity.

Provenance & Evidence