Hydrochloric Acid → 1-Acetyl-4-[(2-amino-6-methylpyridin-4-yl)methyl]piperazin-4-ium chloride

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 4-[(4-acetylpiperazin-1-yl)methyl]-6-methylpyridin-2-ylcarbamate (13-3) was dissolved in CH2Cl2 and the solution was cooled to 0° C. 4.0M HCl in dioxane was added and the solution allowed to warm to room temperature. The reaction was concentrated in vacuo to afford 1-acetyl-4-[(2-amino-6-methylpyridin-4-yl)methyl]piperazin-4-ium chloride. 1-Acetyl-4-[(2-amino-6-methylpyridin-4-yl)methyl]piperazin-4-ium chloride (0.095 g, 0.30 mmol) was dissolved in 2 mL THF. 2-Chloro-1,3-thiazole-5-carbonitrile (0.051 g, 0.36 mmol) and sodium hydride (60% dispersion in mineral oil) (0.028 g, 1.19 mmol) were added and the solution was heated to 75° C. After 4 hours more 2-chloro-1,3-thiazole-5-carbonitrile (0.051 g, 0.36 mmol) was added. After 5.5 hours the solution was allowed to cool to room temperature and concentrated in vacuo. Acetic acid (0.070 mL, 1.19 mmol) was added and was concentrated in vacuo. The residue was purified by reverse phase chromatography (gradient, 5-100% CH3CN/H2O+0.1% TFA). The fractions containing the desired compound were concentrated to dryness to afford the TFA salt of 13-4. TFA salt: 1H NMR (CD3OD) δ 8.04 (s, 1H), 6.99 (s, 1H), 6.95 (s, 1H), 4.13 (bs, 2H), 3.74 (bs, 2H), 3.06 (bs, 6H), 2.61 (s, 3H), 2.13 (s, 3H). [M+H]+=357.1494.

Provenance & Evidence