Tetrahydrofuran → HCID 19037056, compound

Participants

Reaction Steps

To a mixture of 2.7 g of 3-hydroxy-2,2-bis(methoxymethyl)-N-methyl-6-nitro-2H-1-benzopyran-4-carbothioamide, 12 ml of tetrahydrofuran and 46 ml of methanol was added 1.1 g of sodium borohydride (NaBH4) with stirring under ice-cooling and stirred under ice-cooling for 2 hours and subsequently further stirred at room temperature for 24 hours. The reaction solution was vacuum-distilled, water was added therein and the resultant mixture was extracted with methylene chloride. An organic layer was washed with water and dried. The solvent was distilled to obtain 1.0 g of 3,4-dihydro-3-hydroxy-2,2-bis(methoxymethyl)-N-methyl-6-nitro-2H-1-benzopyran-4-carbothioamide. Subsequently, to 700 mg of the obtained benzopyran derivative were added 0.75 g of p-toluenesulfonyl chloride and 11 ml of pyridine. The resultant mixture was refluxed with heating for 30 minutes and the solvent was distilled. Ice water was added to the residue and it was acidified to be hydrochloric acid and extracted with methylene chloride. An organic layer was washed with water and dried and the solvent was distilled. The resultant residue was purified according to silica gel column chromatography (developing solution, MeOH:CH2Cl2 =5:95) to obtain 500 mg of 2,2-bis(methoxymethyl)-N-methyl-6-nitro-2H-1-benzopyran-4-carboxamide with a melting point of 147°-149° C.

Provenance & Evidence