Diethyl Ether → 3-(N,N-diallylamino)-5-methoxychroman

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Reaction Steps

3-Amino-5-methoxychroman hydrochloride (Acta Pharm. Suec. 24 (1987) (5.0 g, 23 mmol), allyl bromide (3.4 mL, 39 mmol), anhydrous K2CO3 (9.6 g, 69 mmol) and DMF (8.0 mL) were stirred under N2 at room temperature for 72 hours. Ether (150 mL) was added, the salts were filtered off by suction and the clear filtrate was concentrated in vacuo. The residue was purified on a silica column eluted with 1000 mL THF-n-hexan (1:9) and 1000 mL THF-hexan (1:3) to afford 3-(N-allylamino)-5-methoxychroman (1.7 g; 33% yield) and 3-(N,N-diallylamino)-5-methoxychroman (3.4 g, 56% yield) as oils. The diallylamino derivative above was isolated as the hydrochloride salt by addition of a slight excess of HCl (approx. 3M in ether) to an ether solution of the amine. The crude HCl salt crystallized on standing, with ether, in the cold. Mp 139°-140° C.

Provenance & Evidence