Dabco → Dimethyl 1,4,6,7-tetrahydropyrano[4,3-b]pyrrole-2,3-dicarboxylate

HRID 1473264

Reaktionsgleichung

[O:1]1[CH2:6][CH2:5][C:4](=[N:7]O)[CH2:3][CH2:2]1.[CH3:9][O:10][C:11]([C:13]#[C:14][C:15]([O:17][CH3:18])=[O:16])=[O:12].C1N2CCN(CC2)C1>C1(C)C=CC=CC=1>[NH:7]1[C:13]([C:11]([O:10][CH3:9])=[O:12])=[C:14]([C:15]([O:17][CH3:18])=[O:16])[C:3]2[CH2:2][O:1][CH2:6][CH2:5][C:4]1=2

Komponenten

Reaktionsbedingungen

Temperatur: 165 °C

Versuchsvorschrift

A suspension of dihydro-2H-pyran-4(3H)-one oxime (7 g, 60.8 mmol), dimethylacetylene dicarboxylate (9.72 ml, 79 mmol), and DABCO (2.046 g, 18.24 mmol) in Toluene (27.5 ml) were heated to 165° C. After 2 h, the reaction mixture was cooled to ambient temperature, concentrated in vacuo and purified by ISCO (0-100% EtOAc-hexanes) to afford dimethyl 1,4,6,7-tetrahydropyrano[4,3-b]pyrrole-2,3-dicarboxylate (3.2 g, 13.38 mmol, 22.00% yield) as a yellow solid. The residue was dissolved in DMF (30 mL), and treated with Cs2CO3 (5.29 g, 16.23 mmol) and 4-fluorobenzyl bromide (2.023 ml, 16.23 mmol). After 2 h, the reaction mixture was partitioned between EtOAc and sat. aq. NH4Cl. The organic layer was washed with water, brine, dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by ISCO (0-50% EtOAc-hexanes; 120 g column) to afford dimethyl 1-(4-fluorobenzyl)-1,4,6,7-tetrahydropyrano[4,3-b]pyrrole-2,3-dicarboxylate (3.92 g, 11.29 mmol, 18.56% yield) as a yellow oil. LCMS (m/z) ES+=348 (M+1).

Aufarbeitung

temperaturethe reaction mixture was cooled to ambient temperature
concentrationconcentrated in vacuo
custompurified by ISCO (0-100% EtOAc-hexanes)

Quellen und Nachweise

ORD-Eintrag: ord-661e15bc5dc7482c8a90bd0547efda7b
Quelldatensatz: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US09012642B2

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