Diethyl Ether → 1-(2-Hydroxyethyl)-4-[4-nitro-3-(propan-2-yloxy)phenyl]pyridinium iodide

HRID 518866Notes

Reaction equation

[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([C:10]2[CH:15]=[CH:14][N:13]=[CH:12][CH:11]=2)=[CH:6][C:5]=1[O:16][CH:17]([CH3:19])[CH3:18])([O-:3])=[O:2].[I:20][CH2:21][CH2:22][OH:23].C(OCC)C>C(#N)C>[I-:20].[OH:23][CH2:22][CH2:21][N+:13]1[CH:12]=[CH:11][C:10]([C:7]2[CH:8]=[CH:9][C:4]([N+:1]([O-:3])=[O:2])=[C:5]([O:16][CH:17]([CH3:19])[CH3:18])[CH:6]=2)=[CH:15][CH:14]=1

Participants

Conditions

Temperature: 85 °C

Procedure

A mixture of 100 mg of 4-[4-nitro-3-(propan-2-yloxy)phenyl]pyridine (see method 1) and 0.075 ml of 2-iodoethanol in 1.7 ml of acetonitrile is heated at 85° C. (bath) for 1 h. 75 μl of 2-iodoethanol are then added and the heating is continued for 15 h at 91° C. The mixture is then concentrated under vacuum, so as to obtain a solid which is taken up with 10 ml of ethyl ether. The resulting heterogeneous mixture is filtered and the solid is rinsed with ethyl ether and dried under reduced pressure, so as to obtain 147 mg of 1-(2-hydroxyethyl)-4-[4-nitro-3-(propan-2-yloxy)phenyl]pyridinium iodide in the form of a solid. 44 g of sodium borohydride are added, at a temperature of about 0° C. (ice/water bath) to a solution of 0.142 g of 1-(2-hydroxyethyl)-4-[4-nitro-3-(propan-2-yloxy)phenyl]pyridinium iodide in 2.6 ml of methanol. After 30 minutes, a few drops of water are added and the mixture is left to return to ambient temperature. The mixture is concentrated to dryness under reduced pressure and then diluted with 150 ml of ethyl acetate. The organic phase is washed successively with 120 ml of a saturated sodium hydrogen carbonate solution and then 70 ml of a saturated sodium chloride solution. The organic phase is dried over anhydrous magnesium sulfate, filtered and then concentrated to dryness under reduced pressure, so as to obtain 90 mg of 2-{4-[4-nitro-3-(propan-2-yloxy)phenyl]-3,6-dihydropyridin-1(2H)-yl}ethanol.

Workup

concentrationThe mixture is then concentrated under vacuum
customso as to obtain a solid which
filtrationThe resulting heterogeneous mixture is filtered
washthe solid is rinsed with ethyl ether
customdried under reduced pressure

Sources & evidence

ORD record: ord-b522a7d5791d4fc4b1d16b30453060ac
Source dataset: uspto-grants-2015_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09115140B2

Reaction notes

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