Carbon Dioxide → 4-((tert-Butoxycarbonyl)amino)-3-methylisothiazole-5-carboxylic acid

HRID 1782155Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1782155
[C:1]([O:5][C:6](=[O:14])[NH:7][C:8]1[C:9]([CH3:13])=[N:10][S:11][CH:12]=1)([CH3:4])([CH3:3])[CH3:2].[Li+].CC([N-]C(C)C)C.[C:23](=[O:25])=[O:24]>C1COCC1>[C:1]([O:5][C:6]([NH:7][C:8]1[C:9]([CH3:13])=[N:10][S:11][C:12]=1[C:23]([OH:25])=[O:24])=[O:14])([CH3:4])([CH3:3])[CH3:2]

Komponenten

5

Edukt 3

HCID 280Carbon DioxideHCID 2724682Lithium diisopropylamideHCID 45790250HCID 45790250, Verbindung

Produkt 1

HCID 547572144-((tert-Butoxycarbonyl)amino)-3-methylisothiazole-5-carboxylic acid

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

To a solution of (3-methyl-isothiazol-4-yl)-carbamic acid tert-butyl ester (method 55) (21.4 g, 100 mmol) in anhydrous THF (200 mL) at -78° C., LDA (139 mL, 1.8 M solution, 250 mmol) was added dropwise over a period of 1 h. The reaction mixture was stirred at that temperature for a further 3 h after which powdered dry ice was added and the reaction slowly allowed to warm to room temperature overnight. The reaction mixture was quenched by adding saturated NH4Cl solution and extracted with ether (3×100 mL) and the combined ether layers were back extracted with satd. NaHCO3 (3×100 mL). The aqueous layers were combined and acidified to pH 5 using 6M HCl and extracted with ether (4×100 mL). The combined ether layers were dried (Na2CO3) and concentrated to give the pure acid as an off white powder. Yield 11 g (39%). 1H NMR (300 MHz) δ 1.47 (s, 9H), 2.44 (s, 3H), 8.53 (bs, 1H), 9.68 (bs, 1H).

Aufarbeitung

  1. additionwas added
  2. customthe reaction
  3. customThe reaction mixture was quenched
  4. additionby adding saturated NH4Cl solution
  5. extractionextracted with ether (3×100 mL)
  6. extractionthe combined ether layers were back extracted with satd
  7. extractionextracted with ether (4×100 mL)
  8. dry with materialThe combined ether layers were dried (Na2CO3)
  9. concentrationconcentrated
  10. customto give the pure acid as an off white powder

Quellen und Nachweise

ORD-Eintrag
ord-31c4b79aa6ad465ca0f7eded1be3fab2
Quelldatensatz
uspto-grants-2009_03
Patentnummer
US07498333B2

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