N-methylhydroxylamine hydrochloride → (4-tert-butoxycarbonyl-3-methyl-benzylidene)-N-methyl-nitrone

HRID 1505238Notes

Reaction equation

[C:1]([O:5][C:6](=[O:16])[C:7]1[CH:12]=[CH:11][C:10]([CH:13]=O)=[CH:9][C:8]=1[CH3:15])([CH3:4])([CH3:3])[CH3:2].[C:17]([O-])(=O)C.[Na+].Cl.[CH3:23][NH:24][OH:25]>O1CCCC1.O.C(OCC)(=O)C.O>[C:1]([O:5][C:6]([C:7]1[CH:12]=[CH:11][C:10]([CH:13]=[C:23]=[N+:24]([CH3:17])[O-:25])=[CH:9][C:8]=1[CH3:15])=[O:16])([CH3:4])([CH3:3])[CH3:2]

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of 4-formyl-2-methyl-benzoic acid tert-butyl ester (Example 4.2) (1.57 g) in tetrahydrofuran/water (3:1) (20 ml) was added sodium acetate (0.67 g) and N-methyl-hydroxylamine hydrochloride (0.69 g). The reaction mixture was stirred at 50° C. for 15 hours. The reaction mixture was diluted with ethyl acetate and water. The phases were separated and the organic layer was washed with water, dried over sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (eluent: methanol/ethyl acetate 5:5) to give (4-tert-butoxycarbonyl-3-methyl-benzylidene)-N-methyl-nitrone (1.43 g) as yellow oil. 1H-NMR (CDCl3, 400 MHz): 8.10 (s, 1H), 8.02 (d, 1H), 7.85 (d, 1H), 7.35 (s, 1H), 3.90 (s, 3H), 2.60 (s, 3H).

Workup

customThe phases were separated
washthe organic layer was washed with water
dry with materialdried over sodium sulfate
concentrationconcentrated
customThe residue was purified by column chromatography on silica gel (eluent: methanol/ethyl acetate 5:5)

Sources & evidence

ORD record: ord-77a0e418616143299f8a38005119bced
Source dataset: uspto-grants-2015_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09216973B2

Reaction notes

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