Sodium borohydride → HCID 18917620, compound

Participants

Reaction Steps

5-Ethyl-3-(4-hydroxybenzoyl)-2-(3-hydroxymethyl-5-undecyl-1,2,4-triazol-4-yl)thiophene (11 g) obtained in Example 21 was dissolved in ethanol (60 ml). Thereto was added sodium borohydride (431 mg) with stirring and the mixture was stirred at room temperature for 1 hour. After the ethanol was distilled away, 5% aqueous sodium hydrogencarbonate was added to the residue and the liberated oily substance was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure and toluene (150 ml) was added to the residue. The mixture was refluxed under heating with stirring and sulfuric acid was gradually added dropwise until the reaction ended. After cooling, 5% aqueous sodium hydrogencarbonate was added thereto and the mixture was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure and the oily substance obtained was crystallized from isopropyl ether-ethyl acetate (4:1) to give 6.5 g of 2-ethyl-4-(4-hydroxy-phenyl)-9-undecyl-4H,6H-thieno[2,3-e][1,2,4]triazolo[3,4-c][1,4]oxazepine as white brown crystals, melting point 96°-98° C.

Provenance & Evidence