Ethyl orthoformate → HCID 68598108, compound

Participants

Reaction Conditions

Reaction Steps

2.20 g (5.27 mmol) of the compound from Example 31A are suspended in 80 ml of triethyl orthoformate and heated to 130° C. Then, over a total period of 8 hours, 5 drops of concentrated sulfuric acid are added each hour to the reaction mixture. It is then stirred at the same temperature overnight. After cooling, excess orthoester is removed in a rotary evaporator, and the crude product is purified by column chromatography (silica gel; mobile phase: initially dichloromethane, then ethyl acetate, finally ethyl acetate/methanol 20:1). The product fractions are concentrated to a volume of about 5 ml. The precipitated product is filtered off and, after washing with ethyl acetate and diethyl ether, dried under high vacuum. 282 mg (12% of theory) of the title compound are obtained in the form of brown crystals.

Provenance & Evidence