Reaktion #992009

Reaktionsgleichung

n-butyl lithium

1-(thiazin-2-yl)-2-amino-6-(α-hydroxy-α-aminocarbonylmethylbenzyl)benzimidazole hydrochloride

1-(thiazin-2-yl)-2-amino-6-benzoylbenzimidazole

hydrochloric acid

bistrimethylsilylacetamide

→

1-(Thiazin-2-yl)-2-amino-6-(α-hydroxy-α-aminocarbonylmethylbenzyl)benzimidazole

Lösungsmittel

water

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo a stirred cold (-78° C.) solution of 37.5 ml
2. 2
   workup.ADDITIONthe addition
3. 3
   workup.ADDITIONdiluted with 300 ml
4. 4
   SonstigeThe organic layer was separated
5. 5
   Sonstigeremoved
6. 6
   ExtraktionThe aqueous mixture was extracted two times with ethyl acetate
7. 7
   Waschenthe combined extracts were washed with water and with brine
8. 8
   Sonstigedried
9. 9
   Sonstigethe solvent was removed by evaporation under reduced pressure
10. 10
    Sonstigeto provide an oil
11. 11
    SonstigeThe oil was triturated with diethyl ether
12. 12
    workup.DISSOLUTIONthe solid was dissolved in dilute hydrochloric acid
13. 13
    SonstigeA precipitate formed
14. 14
    Filtrationwas filtered
15. 15
    Sonstigedried
16. 16
    Sonstigeto give 790 mg

Vorschrift

To a stirred cold (-78° C.) solution of 37.5 ml. of 1.6 molar n-butyl lithium in 50 ml. of tetrahydrofuran was added dropwise over one hour a solution of 50 ml. of tetrahydrofuran containing 14.6 ml. of bistrimethylsilylacetamide. Following the addition, a solution of 4.0 g. of 1-(thiazin-2-yl)-2-amino-6-benzoylbenzimidazole in 300 ml. of tetrahydrofuran was added dropwise over one hour. The reaction mixture was stirred for an additional three hours, and then diluted with 300 ml. of water and allowed to warm to room temperature. The aqueous mixture was acidified with 1 N hydrochloric acid. The organic layer was separated and removed, and the aqueous acid layer was neutralized to pH 7.0 with 1 N sodium hydroxide. The aqueous mixture was extracted two times with ethyl acetate, and the combined extracts were washed with water and with brine, dried, and the solvent was removed by evaporation under reduced pressure to provide an oil. The oil was triturated with diethyl ether and the solid was dissolved in dilute hydrochloric acid. A precipitate formed and was filtered and dried to give 790 mg. of 1-(thiazin-2-yl)-2-amino-6-(α-hydroxy-α-aminocarbonylmethylbenzyl)benzimidazole hydrochloride.

Quelle