Sulfuric Acid → 8-Chloroquinolin-6-ol

HRID 2241964Notes

Reaction equation

Cl.[NH2:2][C:3]1[CH:8]=[CH:7][C:6]([OH:9])=[CH:5][C:4]=1[Cl:10].[N+]([C:14]1[CH:19]=CC=C[CH:15]=1)([O-])=O.B(O)(O)O.S(=O)(=O)(O)O>OCC(CO)O>[Cl:10][C:4]1[CH:5]=[C:6]([OH:9])[CH:7]=[C:8]2[C:3]=1[N:2]=[CH:19][CH:14]=[CH:15]2

Participants

Conditions

Temperature: 120 °C

Procedure

In a 500 ml 3-necked flask equipped with a mechanical stirrer, a reflux condenser, were added in order ferrous sulfate (2.0 g), 4-amino-3-chlorophenol hydrochloride (6.4 g, commercially available), nitrobenzene (2.9 mL) and a solution of boric acid (3.0 g) in glycerol (16 g). Then concentrated sulfuric acid (9 mL) was added drop by drop with cooling. The ice bath was removed and replaced by an oil bath and the mixture was heated cautiously to 120° C. for 2 hours, then at 150° C. and kept stirring under this temperature for 20 hours. After cooling, the reaction was poured on crushed ice and the resulting solution was neutralized with K2CO3. The product separated as a light brown solid that was filtered off, washed with water and hexanes and dried in a vacuum oven (35° C.) overnight giving 7 g (77%) of the desired product. MS (ES) m/z (relative intensity): 180 (M++−H, 100).

Workup

customIn a 500 ml 3-necked flask equipped with a mechanical stirrer, a reflux condenser
temperaturewith cooling
customThe ice bath was removed
customreplaced by an oil bath
temperatureAfter cooling
additionthe reaction was poured
customon crushed ice
customThe product separated as a light brown solid that
filtrationwas filtered off
washwashed with water and hexanes
customdried in a vacuum oven (35° C.) overnight

Sources & evidence

ORD record: ord-c4a54376a06247b79e30244e4454db9f
Source dataset: uspto-grants-2010_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07671056B2

Reaction notes

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