Hydroxylamine → 7-(4-Hydroxyphenyl)-benzofuran-5-carbaldehyde oxime

HRID 1372169Notes

Reaction equation

[OH:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:16]3[O:15][CH:14]=[CH:13][C:12]=3[CH:11]=[C:10]([CH:17]=O)[CH:9]=2)=[CH:4][CH:3]=1.[NH2:19][OH:20].CO.N1C=CC=CC=1>CCOCC>[OH:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:16]3[O:15][CH:14]=[CH:13][C:12]=3[CH:11]=[C:10]([CH:17]=[N:19][OH:20])[CH:9]=2)=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 68 °C

Procedure

To a 25 ml round bottom flask was added 7-(4-hydroxyphenyl)-benzofuran-5-carbaldehyde (400 mg, 1.68 mmol), hydroxylamine hydrochlorode (234 mg, 3.36 mmol), anhydrous MeOH (10.4 ml), and anhydrous pyridine (0.272 ml, 3.36 mmol). The reaction was then heated to 68° C. and the reaction was brought to reflux for 1 h. The reaction was then cooled to room temperature, dilute with ether, and the layers separated. The ether layer was washed with water, dried over anhydrous Na2SO4, passed through a silica plug, and concentrated to 410 mg (96%) product as a yellow solid. The crude material was pure by 1H NMR (−4% cis isomer was detected) and LC-MS (one peak): mp 192–194° C. 1H NMR (300 MHz, DMSO-d6): δ 6.92 (2H, d, J=8.6 Hz), 7.05 (1H, d, J=2.2 Hz), 7.69–7.72 (3H, m), 7.79 (1H, d, J=1.4 Hz), 8.09 (1H, d, J=1.1 Hz), 8.27 (1H, s), 9.74 (1H, s), 11.14 (1H, s); MS (ESI) m/z 254 ([M+H]+).

Workup

temperatureto reflux for 1 h
temperatureThe reaction was then cooled to room temperature
customthe layers separated
washThe ether layer was washed with water
dry with materialdried over anhydrous Na2SO4
concentrationconcentrated to 410 mg (96%) product as a yellow solid

Sources & evidence

ORD record: ord-a25e9452d262461cbe123640c7728b01
Source dataset: uspto-grants-2007_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07157491B2

Reaction notes

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