Synthesis and Anticancer Activity of Novel Chromene Derivatives, Chromeno[2,3-d][1,3]Oxazines, and Chromeno[2,3-d]Pyrimidines.

Background: Several chromene derivatives have a wide variety of biological and pharmacological activity. They had anticancer activity, antimicrobial activity, antituberculosis activity, anticonvulsant activity, antidiabetic activity, antichlolinesterase activity, and inhibitor of monoamine oxidase activity. The above-mentioned activities directed us to synthesize novel chromene derivatives, chromeno[2,3-d][1,3]oxazines, and chromeno[2,3-d]pyrimidines. The starting material was 2- amino-8-(2-chlorobenzylidene)-4-(2-chlorophenyl)-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile.

Methods: Several novel chromene derivatives had been synthesized. Compound 1 reacted with carbon disulfide, and ethyl chloroformate to afford chromene derivatives 2, 3. Chromene derivative 3 reacted with hydrazine dydrate to give compound 4. Chromene derivative 1 reacted with acetic acid and sulphuric acid to produce compounds 5, and 6. Amino derivative 5 reacted with chloroacyl derivative to afford compounds 7a-c which cycalized in dry xylene to afford compounds 8a-c. Chromene derivative 8a reacted with hydroxyl amine to afford compound 9.

Results: The structures of novel synthesized chromene derivatives had been confirmed using mass spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, and elemental analysis. Most of the prepared compounds were screened against liver cancer cell lines (HepG-2), human colon cancer cell lines (HT-29), and breast adenocarcinoma cell lines (MCF-7). Chromene derivative 2 had anticancer activity against human colon cancer cell lines (HT-29) higher than the reference drug doxorubicin. The rest of the tested compounds had anticancer activity against human colon cancer cell lines (HT-29) lower than that of the reference drug doxorubicin. Chromene derivative 5 had anticancer activity against liver cancer cell lines (HepG-2) higher than the reference drug doxorubicin.

Conclusion: Several chromene derivatives had been synthesized and their structures had been confirmed using different spectroscopic techniques. Some of the chromene derivatives that were screened against different cancer cell lines showed promising anticancer activity higher than the reference standard drug. For example, chromene derivative 2 had anticancer activity against human colon cancer cell lines (HT-29) higher than the reference drug doxorubicin. Chromene derivative 5 had anticancer activity against liver cancer cell lines (HepG-2) higher than the reference drug doxorubicin. Chromene derivative 6 had anticancer activity against breast adenocarcinoma cell lines (MCF-7) higher than the standard drug.