ORGN 48 |
| Anna R. Hazlewood1, Yahua Liu2, Sabine S. Hadida2, Liming Huang1, Benjamin J. Petzoldt1, Dewey Fanning1, Timothy D. Neubert1, and Dean M. Wilson3. (1) Discovery Chemistry, Vertex Pharmaceuticals, San Diego, 11010 Torreyana Rd., San Diego, CA 92121, (2) Vertex Pharmaceuticals Incorporated, 11010 Torreyana Rd., San Diego, CA 92121, (3) Drug Discovery, Vertex Pharmaceuticals, San Diego, 11010 Torreyana Rd., San Diego, CA 92121 |
| In the context of "microwave medicinal chemistry", a one pot route to indazoles has been developed, particularly applicable to variants lacking substitutions at the 3-position. Previous routes to these compounds involve multistep syntheses not well suited for parallel synthesis, while the new approach utilizes commercially available o-fluorobenzaldehydes, short reaction times, and gives the desired heterocycles in good yield. The product determining SNAr favors electronically deficient substrates, thus substitutions on the o-fluorobenzaldehyde have a pronounced effect on the outcome. Efforts to scale up the reaction led to the use of a novel hydrazine equivalent (dihydroimadazolyl hydrazine), giving comparable yields and markedly reduced internal pressures; further developments on the use of this synthon as a hydrazine surrogate will be described |
|
Microwave-Assisted Organic Synthesis
1:00 PM-5:05 PM, Sunday, August 22, 2004 Pennsylvania Convention Center -- Ballroom A, Oral
Division of Organic Chemistry |