Dimethyl oxalate → Methyl 4-hydroxy-alpha-oxo-6H-thieno[2,3-b]-thiopyran-5-acetate

HRID 372742Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 372742
C[O-].[Na+].CO[C:6](=[O:11])[C:7]([O:9][CH3:10])=[O:8].[S:12]1[C:16]2[S:17][CH2:18][CH2:19][C:20](=[O:21])[C:15]=2[CH:14]=[CH:13]1>C1C=CC=CC=1>[OH:21][C:20]1[C:15]2[CH:14]=[CH:13][S:12][C:16]=2[S:17][CH2:18][C:19]=1[C:6](=[O:11])[C:7]([O:9][CH3:10])=[O:8]

Komponenten

5

Edukt 3

HCID 11120Dimethyl oxalateHCID 10942334Sodium MethoxideHCID 110302745,6-Dihydro-4H-thieno[2,3-b]thiopyran-4-one

Produkt 1

HCID 22751985Methyl 4-hydroxy-alpha-oxo-6H-thieno[2,3-b]-thiopyran-5-acetateAusbeute 91 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 241BenzeneLösungsmittel2×

Versuchsvorschrift

A mixture of sodium methoxide (21.6 g, 0.4 mole) and dimethyloxalate (47.2 g, 0.4 mole) in benzene (300 ml) is refluxed for 5 min. in order to dissolve most of the solid. To the cooled solution is added a solution of 5,6-dihydro-4H-thieno[2,3-b]-thiopyran-4-one (34 g, 0.2 mole) in benzene (300 ml) and the mixture is stirred for 3 hrs. to give a yellow suspension. The mixture is poured into ice-water mixture (1750 ml). After separating the aqueous layer from the benzene layer, the benzene layer is extracted with 1(N) NaOH solution (250 ml), and the combined aqueous solution is washed once with ether (100 ml) and acidified with (N) HCl. The yellow crystalline glyoxalate is filtered off and dried over P2O5 to give 45.8 g (91%) of the desired product; m.p. 53°-56° C.

Aufarbeitung

  1. temperatureis refluxed for 5 min. in order
  2. dissolutionto dissolve most of the solid
  3. customto give a yellow suspension
  4. customAfter separating the aqueous layer from the benzene layer
  5. extractionthe benzene layer is extracted with 1(N) NaOH solution (250 ml)
  6. washthe combined aqueous solution is washed once with ether (100 ml)
  7. filtrationThe yellow crystalline glyoxalate is filtered off
  8. dry with materialdried over P2O5

Quellen und Nachweise

ORD-Eintrag
ord-3f7e03bc02fb4d5a90f80b73e79af763
Quelldatensatz
uspto-grants-1978_05
Patentnummer
US04092325

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