Oxazole → Methyl 4-butyl-8-(1,3-oxazol-2-yl)-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

HRID 14188

Reaktionsgleichung

[O:1]1[CH:5]=[CH:4][N:3]=[CH:2]1.C([Li])CCC.[CH2:11]([N:15]1[C:20]2[CH:21]=[C:22]([C:26]([O:28][CH2:29]C)=[O:27])[CH:23]=[C:24](I)[C:19]=2[O:18][CH2:17][CH2:16]1)[CH2:12][CH2:13][CH3:14]>O1CCCC1.C(OCC)(=O)C.[Cl-].[Zn+2].[Cl-]>[CH2:11]([N:15]1[C:20]2[CH:21]=[C:22]([C:26]([O:28][CH3:29])=[O:27])[CH:23]=[C:24]([C:2]3[O:1][CH:5]=[CH:4][N:3]=3)[C:19]=2[O:18][CH2:17][CH2:16]1)[CH2:12][CH2:13][CH3:14]

Komponenten

Reaktionsbedingungen

Temperatur: -70 °C

Versuchsvorschrift

To a −70° C. solution of oxazole (227 mg) in tetrahydrofuran (10 mL) was added n-butyllithium (2.5 M in hexanes, 2 mL). After stirred at −70° C. for 30 min, zinc chloride (1 M in ethyl ether, 13 mL) was added. The mixture was warmed to 0° C. for 1 h. To this mixture was then added ethyl 4-butyl-8-iodo-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (600 mg, 1.6 mmol) in THF (5 mL) followed by tetrakis triphenylphosphine palladium(0) (115 mg). The mixture was heated at reflux for 3 h, diluted with ethyl acetate (300 mL) and washed with water followed by brine. The organic solution was dried (sodium sulfate) and concentrated under reduced pressure. Purification by silica gel plug (1:1 acetate/hexanes) provided 363 mg of the title compound: 1H NMR (300 MHz, CDCl3) δ 7.96, 7.73, 7.40, 7.28, 4.44, 3.90, 3.43, 3.34, 1.61, 1.41, 0.98.

Aufarbeitung

temperatureThe mixture was warmed to 0° C. for 1 h
temperatureThe mixture was heated
temperatureat reflux for 3 h
washwashed with water
dry with materialThe organic solution was dried (sodium sulfate)
concentrationconcentrated under reduced pressure
customPurification by silica gel plug (1:1 acetate/hexanes)

Quellen und Nachweise

ORD-Eintrag: ord-89e7e13a6e064a79961c44e05570b1e8
Quelldatensatz: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US07727997B2

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