Hydroxyamine hydrochloride → 4-(Hydroxyimino-methyl)-2-methyl-benzoic acid tert-butyl ester

HRID 467943Notes

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].Cl.[NH2:18][OH:19].C(=O)([O-])O.[Na+]>C(O)C.O>[C:1]([O:5][C:6](=[O:16])[C:7]1[CH:12]=[CH:11][C:10]([CH:13]=[N:18][OH:19])=[CH:9][C:8]=1[CH3:15])([CH3:4])([CH3:3])[CH3:2]

Participants

Conditions

Temperature: 50 °C

Procedure

To a suspension of 4-formyl-2-methyl-benzoic acid tert-butyl ester (Example I17) (60.3 g) and hydroxylamine hydrochloride (38.05 g) in ethanol (580 ml) was added a solution of sodium hydrogen carbonate (46 g) in water (60 ml). The reaction mixture was stirred at 50° C. for 3.5 hours. The solvent was removed and the residue 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 crystallized from ethyl acetate and heptane to give 4-(hydroxyimino-methyl)-2-methyl-benzoic acid tert-butyl ester (35.72 g) as a white crystalline powder. 1H-NMR (CDCl3, 400 MHz): 7.86 (s, 1H), 7.70 (s, 1H), 7.45 (m, 2H), 2.60 (s, 3H), 1.60 (s, 9H).

Workup

customThe solvent was removed
additionthe residue diluted with ethyl acetate and water
customThe phases were separated
washthe organic layer was washed with water
dry with materialdried over sodium sulfate
concentrationconcentrated
customThe residue was crystallized from ethyl acetate and heptane

Sources & evidence

ORD record: ord-2d3dcf97f3034d0a915a60011b13812f
Source dataset: uspto-grants-2014_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08623896B2

Reaction notes

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