Diisopropylethylamine → Benzimidazole

Participants

Reaction Steps

Benzimidazole analogs were synthesized by a Mitsunobu coupling (Zaragoza, F. Tetrahedron 2001, 57, 5451-5454 and Zaragoza, F.; Stephensen, H. J. Org. Chem. 2001, 66, 2518-2521) of 6-mercaptopurine riboside with benzimidazole-methyl alcohol (Kimura, T.; Takase, Y.; Hayashi, K.; Tanaka, H.; Ohtsuka, I.; Saeki, T.; Kogushi, M.; Yamada, T.; Fujimori, T.; Saitou, I.; Akasaka, K. J. Med. Chem. 1993, 36, 1630-1640), in the presence of (cyanomethyl)trimethylphosphonium iodide (36) and diisopropylethylamine (DIPEA) in propionitrile (Scheme 4). After refluxing of this mixture for 18 hr, water was added and the product precipitated. The direct use of alcohol 34 and 35 is an advantage of this method compared to the previous reactions. (Temple, C.; Kussner, C. L.; Montgomery, J. A. J. Org. Chem. 1968, 11, 41-43). These alcohols were prepared from reduction of the appropriate esters via standard procedures. (Sun, Q.; Gatto, B.; Yu, C.; Liu, A.; Liu, L. F.; LaVoie, E. J. J. Med. Chem. 1995, 38, 3638-3644).

Provenance & Evidence