1,4,7,10-Tetraazacyclododecane was synthesized through 4 steps by using easily available diphenylsulfonium triflate as a key annulation reagent. The reaction condition was very mild and the yield was high. After oxidation and hydrolysis, 1,4,7,10-Tetraazacyclododecane, which had been proven to be the pivotal precursor for a wide range of MRI contrast reagents, was produced in an overall yield of 31&percnt.

中文翻译：

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乙烯基ulf盐的串联反应新颖合成1,4,7,10-四氮杂环十二烷

1,4,7,10-四氮杂环十二烷通过使用易得的三氟甲磺酸二苯s作为关键的环化试剂，通过4个步骤合成。反应条件非常温和，产率高。经过氧化和水解后，已生产出1,4,7,10-四氮杂环十二烷，已被证明是各种MRI造影剂的关键前体，总产率为31％。