Reaktion #70770

Reaktionsgleichung

ethyl 5-cyano-4-methyl-6-oxo-1,6-dihydropyridine-2-carboxylate

trimethyloxonium tetrafluoroborate

NaOH

→

ethyl 5-cyano-6-methoxy-4-methylpicolinate

Ausbeute 52.9%

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe reaction was rinsed down with CH2Cl2
2. 2
   Sonstige(The reaction
3. 3
   workup.STIRRINGAfter stirring for 10 minutes the mixture
4. 4
   workup.ADDITIONwas poured into a separatory funnel
5. 5
   SonstigeThe CH2Cl2 phase was removed
6. 6
   Trocknendried (Na2SO4)
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under vacuum
9. 9
   SonstigePurification by silica gel chromatography (Analogix SF25-40 g, 50 to 100% CH2Cl2 in hexanes)

Vorschrift

To a stirred suspension of ethyl 5-cyano-4-methyl-6-oxo-1,6-dihydropyridine-2-carboxylate (2.0 g, 9.70 mmol) in CH2Cl2 (25 mL) was added trimethyloxonium tetrafluoroborate (2.0 g, 13.52 mmol). The reaction was rinsed down with CH2Cl2 and stirred at RT for 24 hr. (The reaction eventually cleared up.) To the reaction was added 1N NaOH (75 mL). After stirring for 10 minutes the mixture was poured into a separatory funnel. The CH2Cl2 phase was removed, dried (Na2SO4), filtered and concentrated under vacuum. Purification by silica gel chromatography (Analogix SF25-40 g, 50 to 100% CH2Cl2 in hexanes) gave the product ethyl 5-cyano-6-methoxy-4-methylpicolinate (1.13 g, 5.13 mmol, 52.9% yield) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 7.75 (s, 1H), 4.37 (q, J=7.1 Hz, 2H), 4.03 (s, 3H), 2.55 (s, 3H), 1.33 (t, J=7.2 Hz, 3H). MS (ES)+m/e 221.2 [M+H]+.

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