Hydrochloric Acid → HCID 11644329, compound

Participants

Reaction Steps

A solution of Br2 (0.73 ml, 14.3 mmol, 1 equiv.) in DMF (5 ml) is added over 15 min to a solution of N-methoxycarbonyl-1,2-dihydropyridine 1 (2 g, 14.3 mmol, 1 equiv.) and of Boc-guanidine (9.15 g, 57.5 mmol, 4 equiv.) in a mixture of DMF (10 ml) and of CH3CN (5 ml) under cold conditions (0-5° C.) and under argon. The reaction being complete from the end of the addition of bromine, the reaction mixture is poured onto ice-cold water (600 ml). The aqueous phase is subsequently extracted with DCM (3×200 ml). The crude product obtained (3.5 g) is dissolved in the minimum amount of methanol, followed by addition of a 2N hydrochloric acid solution (10 ml). The solution is brought to reflux in [illegible] for 5 min. After cooling, the reaction mixture is washed with ether and then evaporated to dryness to give 2.4 g of the deprotected compound 4 with a yield of 71% over the two stages.

Provenance & Evidence