The novel and green synthesis of 6-amino-4-phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile via the solvent-free biginelli multi-component reaction catalysed by Choline chloride/2ZnCl2 - Tran, Trang; Duong, Thang; Luu, Xuan Thi (VNUHCM Journal of Advanced Research in Natural Sciences, 2024)