N-Phenylhydroxylamine → Isoxazolo(4,5-c)quinolin-3(2H)-one, 2-phenyl-

HRID 280108

Reaction equation

[C:1]1([NH:7][OH:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[H-].[Na+].Cl[C:12]1[C:21]2[C:16](=[CH:17][CH:18]=[CH:19][CH:20]=2)[N:15]=[CH:14][C:13]=1[C:22](OCC)=[O:23]>O1CCCC1>[C:1]1([N:7]2[C:22](=[O:23])[C:13]3[CH:14]=[N:15][C:16]4[CH:17]=[CH:18][CH:19]=[CH:20][C:21]=4[C:12]=3[O:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

Conditions

Temperature: 5 °C

Procedure

A solution of 9 g of N-phenylhydroxylamine [described in Organique Synthese, Vol. 1, p. 445]was added dropwise at 0° C. with stirring under an inert atmosphere to a suspension of 3.85 g of 50% sodium hydride in 100 ml of tetrahydrofuran, and after stirring at 5° C. for 30 minutes, a solution of 18.8 g of ethyl 4-chloro-3-quinoline carboxylate in 100 ml of tetrahydrofuran was added at 0° C. The mixture was stirred for 16 hours at ambient temperature and after concentration to dryness under reduced pressure, the residue was taken up in ice. The mixture was extracted with methylene chloride and the organic phase was washed, dried, and concentrated to dryness. The residue was purified by chromatography on silica (eluent: ethyl acetate) to obtain 1.2 g of 2-phenylisoxazolo(4,5-c)quinolin-3-(2H)-one (corresponding to the 3rd eluted fraction) melting at 163° C. after crystallization from isopropyl ether.

Workup

addition445]was added dropwise at 0° C.
stirringThe mixture was stirred for 16 hours at ambient temperature
concentrationafter concentration to dryness under reduced pressure
extractionThe mixture was extracted with methylene chloride
washthe organic phase was washed
customdried
concentrationconcentrated to dryness
customThe residue was purified by chromatography on silica (eluent: ethyl acetate)

Sources & evidence

ORD record: ord-769b44905db54d1fb528b59d7b4a14de
Source dataset: uspto-grants-1986_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04588731

Linked notes

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