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

HRID 37658Notes

Reaction equation

HRID 37658 reaction equation
Cl.[NH2:2][CH:3]1[CH2:12][C:11]2[C:6](=[CH:7][CH:8]=[CH:9][C:10]=2[O:13][CH3:14])[O:5][CH2:4]1.[CH2:15](Br)[CH:16]=[CH2:17].C([O-])([O-])=O.[K+].[K+].[CH3:25][N:26]([CH:28]=O)[CH3:27].[CH3:30][CH2:31]OCC>>[CH2:17]([NH:2][CH:3]1[CH2:12][C:11]2[C:6](=[CH:7][CH:8]=[CH:9][C:10]=2[O:13][CH3:14])[O:5][CH2:4]1)[CH:16]=[CH2:15].[CH2:28]([N:26]([CH:25]1[CH2:12][C:11]2[C:10](=[CH:9][CH:8]=[CH:7][C:6]=2[O:5][CH3:4])[O:13][CH2:14]1)[CH2:27][CH:16]=[CH2:17])[CH:30]=[CH2:31]

Participants

7

Reactant 5

HCID 3283Diethyl EtherHCID 6228DimethylformamideHCID 7841Allyl bromideHCID 11430Potassium CarbonateHCID 139289495-Methoxychroman-3-amine hydrochloride

Product 2

HCID 141036013-(N,N-diallylamino)-5-methoxychromanYield 56%HCID 141036023-(N-Allylamino)-5-methoxychromanYield 33%

Procedure

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.

Workup

  1. filtrationthe salts were filtered off by suction
  2. concentrationthe clear filtrate was concentrated in vacuo
  3. customThe residue was purified on a silica column
  4. washeluted with 1000 mL THF-n-hexan (1:9) and 1000 mL THF-hexan (1:3)

Sources & evidence

ORD record
ord-a1f2dedf384e40ec97a1faca6d0765e1
Source dataset
uspto-grants-1995_05
Patent number
US05420151

Reaction notes

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