Synthesis of compounds related to the anti-migraine drug eletriptan hydrobromide

• Suri Babu Madasu,
• Nagaji Ambabhai Vekariya,
• M. N. V. D. Hari Kiran,
• Badarinadh Gupta,
• Aminul Islam,
• Paul S. Douglas and
• Korupolu Raghu Babu

Beilstein J. Org. Chem. 2012, 8, 1400–1405, doi:10.3762/bjoc.8.162

• palladium acetate in tetrahydrofuran, as in the following reaction scheme (Scheme 4). The content of indole pyrrolidine 6 in bromoindolyl pyrrolidine 9 is controlled by its specification to not more than 0.5%. However, during basic hydrolysis of enesulfone derivative 12, unreacted N-acetyl bromoindolyl

• compounds of eletriptan hydrobromide. Synthetic route of eletriptan hydrobromide. Reagents and conditions: (i) Acetic anhydride, TEA, DMF, 90–100 °C; (ii) palladium acetate, tri-(o-tolyl)phosphine, TEA, DMF, 90–100 °C; (iii) methanol, K2CO3, acetonitrile, H2O, 5–10 °C; (iv) palladium on carbon, acetone, H2O

• % yield. Synthesis of impurity 5. Reagents and conditions: (i) Acetic anhydride, TEA, DMF, 90–100 °C; (ii) palladium acetate, tri-(o-tolyl)phosphine, K2CO3, triethyl borane in THF (1 M), THF, 64–66 °C; (iii) methanol, K2CO3, methylene chloride, H2O, 5–10 °C and 85% yield. Debromination of 9 to 6. Reagents

Synthesis, reactivity and biological activity of 5-alkoxymethyluracil analogues

• Lucie Brulikova and
• Jan Hlavac

Beilstein J. Org. Chem. 2011, 7, 678–698, doi:10.3762/bjoc.7.80

• derivatives of 2'-deoxyuridine 28, 2'-fluoro-2'-deoxyuridine 29 and uridine 30 (Scheme 4). The authors utilized the known palladium acetate-triphenylphosphine-catalyzed reaction of 5-iodo-2'-deoxyuridine with vinyl acetate for the preparation of 5-vinyl-2'-deoxyuridine (9) [14]. However, attempts to prepare 2

Pd-catalyzed decarboxylative Heck vinylation of 2-nitrobenzoates in the presence of CuF₂

• Lukas J. Gooßen,
• Bettina Zimmermann and
• Thomas Knauber

Beilstein J. Org. Chem. 2010, 6, No. 43, doi:10.3762/bjoc.6.43

• equivalents (entry 1). A further reduction to 1 or even 0.5 equivalents led to decreased yields (entries 2 and 3). We next investigated several palladium sources and found that palladium acetate gave yields comparable to the substantially more expensive palladium hexafluoroacetylacetonate (entry 4). In all

• undesired nitrobenzene (4a) (entries 19 and 20). Thus, under optimized conditions, potassium 2-nitrobenzoate was decarboxylated and coupled with styrene in the presence of 2 mol % palladium acetate, 4 mol % 1,4,5-triazanaphthalene, 2 equivalents of copper fluoride, 0.5 equivalents of p-benzoquinone, and

A short and efficient synthesis of valsartan via a Negishi reaction

• Samir Ghosh,
• A. Sanjeev Kumar and
• G. N. Mehta

Beilstein J. Org. Chem. 2010, 6, No. 27, doi:10.3762/bjoc.6.27

• of Q-phos and palladium acetate in tetrahydrofuran at 75 °C produced methyl N-pentanoyl-N-{[2'-(1-trityl-1H-tetrazol-5-yl)biphenyl-4-yl]methyl}-L-valinate (7) in 80% yield. Hydolysis of 7 with 3 N NaOH in methanol gave valsartan 8 [11]. Conclusion In summary, a highly efficient approach to the

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• addition to the corresponding thiolactam. The crucial intramolecular Heck cyclisation was carried out with palladium acetate, tri-o-tolylphosphine and triethylamine to give 218 in 82% yield. It was discovered that transformation of compound 218 into an aziridinomitosane was unexpectedly difficult. The most

Development of potential manufacturing routes for substituted thiophenes – Preparation of halogenated 2-thiophenecarboxylic acid derivatives as building blocks for a new family of 2,6-dihaloaryl 1,2,4-triazole insecticides

• John W. Hull Jr.,
• Duane R. Romer,
• David E. Podhorez,
• Mezzie L. Ash and
• Christine H. Brady

Beilstein J. Org. Chem. 2007, 3, No. 23, doi:10.1186/1860-5397-3-23

• palladium acetate as the catalyst precursor, was successfully modified in our hands [18] to allow for the use of heterogeneous palladium on carbon catalyst. The ability to use a heterogeneous form of catalyst opens the door for catalyst recycle for an industrially viable process, although carbonylation

• rates were found to be slower for the heterogeneous catalyst compared to homogeneous palladium acetate. The use of DPPP was required for successful conversion to carbonylation product, even with the use of heterogeneous Pd/C catalyst. Carbonylation of 8 in an Et3N/H2O solvent system gave acid 19, while