Tetrahydro-4H-pyran-4-ol → 2-Hydroxy-4-nitro-benzoic acid tetrahydro-pyran-4-yl ester

HRID 1910792Notes

Reaction equation

[OH:1][C:2]1[CH:10]=[C:9]([N+:11]([O-:13])=[O:12])[CH:8]=[CH:7][C:3]=1[C:4](Cl)=[O:5].[OH:14][CH:15]1[CH2:20][CH2:19][O:18][CH2:17][CH2:16]1>C1COCC1.N1C=CC=CC=1.CN(C)C1C=CN=CC=1.O>[O:18]1[CH2:19][CH2:20][CH:15]([O:14][C:4](=[O:5])[C:3]2[CH:7]=[CH:8][C:9]([N+:11]([O-:13])=[O:12])=[CH:10][C:2]=2[OH:1])[CH2:16][CH2:17]1

Participants

Conditions

Temperature: 45 °C

Procedure

2-Hydroxy-4-nitro-benzoyl chloride (0.82 g, 4.07 mmol) in THF (15 mL) was added portionwise to a solution of 4-hydroxytetrahydropyran (0.8 mL, 8.1 mmol) in pyridine (4 μL) at 0° C., followed by a catalytic amount of 4-(dimethylamino)-pyridine (DMAP). The mixture was maintained overnight at 40-50° C. then diluted with water and extracted with ethyl acetate. The organic extract was washed successively with saturated sodium bicarbonate solution, water and brine solution, dried and concentrated to give a residue which was triturated with a mixture of DCM and petroleum ether. The residue was purified by flash column chromatography on silica, eluting with ethyl acetate/petroleum ether (2-15%) to give 2-hydroxy-4-nitro-benzoic acid tetrahydro-pyran-4-yl ester (0.32 g, 29%).

Workup

extractionextracted with ethyl acetate
extractionThe organic extract
washwas washed successively with saturated sodium bicarbonate solution, water and brine solution
customdried
concentrationconcentrated
customto give a residue which
customwas triturated with a mixture of DCM and petroleum ether
customThe residue was purified by flash column chromatography on silica
washeluting with ethyl acetate/petroleum ether (2-15%)

Sources & evidence

ORD record: ord-2441a56449c840ee8da829b3db925ebd
Source dataset: uspto-grants-2013_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08604029B2

Reaction notes

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