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Lee D, Lee S, Liu KH, Bae JS, Baek DJ, Lee T. Solid-Phase Synthesis of 1,3,7,8-Tetrasubstituted Xanthine Derivatives on Traceless Solid Support. ACS COMBINATORIAL SCIENCE 2016; 18:70-4. [PMID: 26616892 DOI: 10.1021/acscombsci.5b00148] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Traceless solid-phase synthesis of 1,3,7,8-tetrasubstituted xanthine (1,3,7,8-tetrasubstituted 1H-purine-2,6(3H,7H)-dione) derivatives has been developed. The solid-phase synthetic route began on a solid supported N'-cyano-N-substituted carbamimidothioate, which was prepared from cyanamide, isothiocyanate, and Merrifield resin. After N-alkylation of carbamimidothioate resin with ethyl 2-bromoacetate, an imidazole ring is introduced by Thorpe-Ziegler-type cyclization. The resulting imidazole resin is converted to 1,3,7-trisubstituted xanthine resin using sequential reactions, such as Lewis acid-catalyzed urea formation, pyrimidine ring cyclization, and N-alkylation. After oxidation of sulfides to sulfones, traceless cleavage with amine or thiol nucleophiles afforded the desired 1,3,7,8-tetrasubstituted xanthines in good purities and overall yields (eight-steps; 36 examples). This efficient solid-phase synthesis enables the incorporation of four diversity points into the preparation of the 1,3,7,8-tetrasubstituted xanthines.
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Affiliation(s)
- Doohyun Lee
- College
of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701, Korea
| | - Seungyeon Lee
- College
of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701, Korea
| | - Kwang-Hyeon Liu
- College
of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701, Korea
| | - Jong-Sup Bae
- College
of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701, Korea
| | - Dong Jae Baek
- College
of Pharmacy, Natural Medicine Research Institute, Mokpo National University, 1666 Youngsan-ro, Muan-gun, Jeonnam 534-729, Korea
| | - Taeho Lee
- College
of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 702-701, Korea
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