Trimethylsilylacetylene → Ethyl 2-ethynyl-4-methylthiazole-5-carboxylate

HRID 2381774Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2381774
Br[C:2]1[S:3][C:4]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:5]([CH3:7])[N:6]=1.[CH:13](N(CC)C(C)C)(C)[CH3:14].C[Si](C#C)(C)C>C1(C)C=CC=CC=1.[Cu]I.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[C:13]([C:2]1[S:3][C:4]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:5]([CH3:7])[N:6]=1)#[CH:14]

Komponenten

7

Edukt 3

HCID 66111TrimethylsilylacetyleneHCID 81531DiisopropylethylamineHCID 2824057Ethyl 2-bromo-4-methyl-1,3-thiazole-5-carboxylate

Produkt 1

HCID 59179676Ethyl 2-ethynyl-4-methylthiazole-5-carboxylateAusbeute 79,4 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)KatalysatorHCID 178418476HCID 178418476, VerbindungKatalysatorHCID 1140TolueneLösungsmittel

Reaktionsbedingungen

Temperatur
40 °C

Versuchsvorschrift

To a solution of ethyl 2-bromo-4-methylthiazole-5-carboxylate (0.50 g, 2.00 mmol) in anhydrous toluene (5 mL) was added copper(I) iodide (0.008 g, 0.040 mmol), dichlorobis(triphenylphosphine)palladium(II) (0.028 g, 0.040 mmol) and N,N-diisopropylethylamine (0.52 mL, 3.00 mmol). The reaction mixture was degassed and the reaction flask was flashed and filled with nitrogen followed by the addition of trimethylsilylacetylene (0.42 mL, 3.00 mmol). The reaction mixture was heated at 40° C. for 5 hours, cooled to ambient temperature, poured onto a silica gel pad and eluted with hexanes and hexanes/ethyl acetate (10/1). The collections were concentrated in vacuo and the obtained clear oil was dissolved in dichloromethane (5 mL) and treated with 10% aqueous sodium hydroxide (0.5 mL) at ambient temperature for 1 hour. The reaction mixture was diluted with dichloromethane (15 mL), washed with water (7 mL) and brine (7 mL). The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to afford the title compound as a yellowish solid (0.31 g, 77%): 1H NMR (300 MHz, CDCl3) δ 4.24 (q, J=7.1 Hz, 2H), 3.53 (s, 1H), 2.63 (s, 3H), 1.27 (t, J=7.1 Hz, 3H); MS (ES+) m/z 196.2 (M+1).

Aufarbeitung

  1. customThe reaction mixture was degassed
  2. additionfilled with nitrogen
  3. temperaturecooled to ambient temperature
  4. additionpoured onto a silica gel pad
  5. washeluted with hexanes and hexanes/ethyl acetate (10/1)
  6. concentrationThe collections were concentrated in vacuo
  7. dissolutionthe obtained clear oil was dissolved in dichloromethane (5 mL)
  8. additiontreated with 10% aqueous sodium hydroxide (0.5 mL) at ambient temperature for 1 hour
  9. additionThe reaction mixture was diluted with dichloromethane (15 mL)
  10. washwashed with water (7 mL) and brine (7 mL)
  11. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  12. filtrationfiltered
  13. concentrationconcentrated in vacuo

Quellen und Nachweise

ORD-Eintrag
ord-a66d95749c934cdd8b7d2dae639207ee
Quelldatensatz
uspto-grants-2012_09
Patentnummer
US08258160B2

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