Symmetric and asymmetric carbonates were synthesized by using alkyl or aryl 4,5-dichloro-6-oxopyridazin-1(6 H )-carboxylates. Five aryl 4,5-dichloro-6-oxopyridazin-1(6 H )-carboxylates were converted into the corresponding diaryl carbonates in good to excellent yields by treatment with potassium carbonate in refluxing THF. When the 4,5-dichloro-6-oxopyridazin-1(6 H )-carboxylates were treated with aliphatic or aromatic alcohols in the presence of potassium tert -butoxide in toluene at room temperature, they gave the corresponding symmetric or asymmetric carbonates in moderate to excellent yields. Alkyl and aryl 4,5-dichloro-6-oxopyridazin-1(6 H )-carboxylates are therefore efficient, stable, and ecofriendly alternatives to chloroformates.

中文翻译：

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烷基和芳基 4,5-Dichloro-6-oxopyridazin-1(6H)-carboxylates：用于合成对称和不对称碳酸酯的氯甲酸酯的实用替代品

通过使用烷基或芳基 4,5-dichloro-6-oxopyridazin-1(6 H)-carboxylates 合成对称和不对称碳酸酯。通过在回流的四氢呋喃中用碳酸钾处理，五种芳基 4,5-二氯-6-氧代哒嗪-1(6 H)-羧酸酯以良好到极好的产率转化为相应的碳酸二芳基酯。当 4,5-二氯-6-氧代哒嗪-1(6 H )-羧酸酯在叔丁醇钾的存在下在甲苯中在室温下用脂肪族或芳香族醇处理时，它们得到相应的对称或不对称碳酸酯。以优异的产量。因此，烷基和芳基 4,5-二氯-6-氧代哒嗪-1(6 H )-羧酸酯是氯甲酸酯的高效、稳定且环保的替代品。