Side-Chain Manipulation with a Purine Derivative Unexpected

Side-Chain Manipulation with a Purine Derivative Unexpected 

Reaction of 6-mercaptopurine with sodium bicarbonate and epichlorohydrin in ethanol for 7 days at room temperature gave the expected chlorohydrin derivative. Unexpectedly, when this was treated with two equivalents of sodium methoxide in methanol at room temperature for 24 hours it did not give either epoxide or methoxy containing derivatives. Instead, the product, obtained in 32% yield, was the substituted thietane 1. 

Treatment of 5-cyanomethylisoxazolines 1 with a catalytic amount of DBU in boiling xylene gives good to excellent yields of 6-substituted-2-aminopyridine N-oxides. 

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