A Sequential One-pot Three-component Synthesis of 2-Oxindole Scafold Containing Dihydropyrazine by Using Triethylammonium thiolates

Pyrazines and its derivatives have shown different biological activities such as cytotoxic and antitumor, antimycobacterial, antituberculosis, antifungal, antibacterial and etc. The most common synthesis method of pyrazines is dehydrogenation of 2,3- dihydropyrazines which are prepared from reaction between 1,2-diamines and 1,2- dicarbonyl compounds. Furthermore, dihydropyazines also showed DNA strandbreaking activity and growth inhibition of Escherichia coli. Therefore, dihydropyrazines and pyrazines are amongst the most scaffolds used in natural products and chemotherapeutic agents.1 Oxindoles, especially substituted oxindoles at 3-Position have been exhibited antibacterial, antiinflammatory, antifungal, antimalarial, antitumor, antimicrobial, and antiviral activities. Moreover, the oxindole framework has been found in manybiological and pharmaceutical active compounds and natural products.2 Because of the importance and applications of compounds contain of dihydropyrazine ring, and 2-oxindole skeleton, and in order to develop our studies on the synthesis of oxindole derivatives,3 we report the one-pot three component reaction between triethylammonium (Z)-2-oxo-1-(2-oxoindolin-3-ylidene)-2- phenylethane-1-thiolate 1, methyl iodide 2 and 1,2-diamines 3 in DMF at room temperature for the preparation of (Z)-3-(3-aryl-5,6-dihydro-2(1H)-pyrazinyliden)-1Hindol- 2-ones 4