Reaktion #332685

Reaktionsgleichung

Oxalyl chloride

6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-7-methyl-3-(1,3-thiazol-2-yl)-1,2-benzoxazole-5-carboxylic acid

Intermediate 326

6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-7-methyl-3-(1,3-thiazol-2-yl)-1,2-benzoxazole-5-carboxylic acid

lithium tri(t-butoxy)aluminum hydride

→

product

6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-7-methyl-3-(1,3-thiazol-2-yl)-1,2-benzoxazol-5-carbaldehyde

Lösungsmittel

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeSolvent was removed under reduced pressure
2. 2
   workup.DISSOLUTIONthe residue was dissolved in THF (10 mL)
3. 3
   Temperaturthe solution was cooled to −78° C.
4. 4
   workup.STIRRINGit was stirred for 30 mins at the same temperature
5. 5
   SonstigeThe reaction was quenched with 1.5N hydrochloric acid
6. 6
   Extraktionextracted with ethyl acetate
7. 7
   Trocknenthe combined organic layers were dried over sodium sulfate
8. 8
   Sonstigethe solvent was removed
9. 9
   SonstigeThe brown viscous oil thus obtained
10. 10
    Sonstigewas purified by silica gel column chromatography (20% ethyl acetate in hexane)

Vorschrift

Oxalyl chloride (0.31 g, 2.4 mmol) was added to a stirred solution of 6-[(2R,6S)-2,6-dimethylmorpholin-4-yl]-7-methyl-3-(1,3-thiazol-2-yl)-1,2-benzoxazole-5-carboxylic acid (Intermediate 326, 0.18 g, 0.4 mmol) and two drops DMF in dichloromethane (5 mL) at 0° C. and the mixture was stirred at room temperature for 2 hours. Solvent was removed under reduced pressure and the residue was dissolved in THF (10 mL) and the solution was cooled to −78° C. and 1M solution of lithium tri(t-butoxy)aluminum hydride (0.28 g, 1.1 mmol) was added slowly and it was stirred for 30 mins at the same temperature. The reaction was quenched with 1.5N hydrochloric acid and extracted with ethyl acetate, the combined organic layers were dried over sodium sulfate and the solvent was removed. The brown viscous oil thus obtained was purified by silica gel column chromatography (20% ethyl acetate in hexane) affording the product as yellow solid. Yield: 0.06 g (35%).

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