Pyridine → N-methyl-(3-thioacetyl)propionamide

Participants

Reaction Steps

Acetylthiopropionic acid (0.5 g, 3.38×10-3 mol, see Example 2), methylamine hydrochloride (0.25 g, 3.7×10-3 mol) and pyridine (0.58 ml, 7.2×10-3 mol) were dissolved in 15 ml anhydrous dimethylformamide. The reaction was started by addition of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.71 g, 3.7×10-3 mol). The reaction was stirred over argon at room temperature for 5 hr. The solvents were removed in vacuo to afford a yellow oil. After addition of 5 ml water and 1 ml 0.5M potassium phosphate, pH 7, to the oil, the pH of the solution was carefully adjusted to 7.0 with 10N KOH. The aqueous solution was extracted 4 times, each with 25 ml methylene chloride. The organic phase was dried with anhydrous magnesium sulfate and filtered. The solvents were removed in vacuo, 10 ml ethyl alcohol was added to the residue, and the solvent was removed in vacuo to remove traces of pyridine. Ethyl acetate (1.5 ml) was added to the crystalline residue and the slight precipitate was filtered. The solvent was removed in vacuo and the compound was dried overnight in a vacuum desiccator. 0.43 g of the desired compound was recovered which melted at 67°-70° C.

Provenance & Evidence