@article{figueroa-villar_clemente_silva_2001,  title={Synthesis and spectroscopic characterization of 5-diaminomethylidene barbiturates},  volume={12},  ISSN={0103-5053},  url={https://doi.org/10.1590/S0103-50532001000200020},  DOI={10.1590/S0103-50532001000200020},  number={2},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Figueroa-Villar, José D. and Clemente, Fábio C. and Silva, Ana C. C. da},  year={2001},  month={Mar},  pages={247–254} }