Vol.:(0123456789) Research on Chemical Intermediates https://doi.org/10.1007/s11164-020-04279-5 1 3 Nano‑Co‑[4‑chlorophenyl‑salicylaldimine‑ pyranopyrimidine dione]Cl 2 as a new Schif base complex and catalyst for the one‑pot synthesis of some 4H‑pyrimido[2,1‑b]benzazoles Ahmad Reza Moosavi‑Zare 1  · Hamid Goudarziafshar 1  · Parva Fashi 1 Received: 8 May 2020 / Accepted: 18 September 2020 © Springer Nature B.V. 2020 Abstract Nano-Co-[4-clolorophenyl-salsylaldimine-pyranopyrimidine dione]Cl 2 {Nano-[Co- 4CSP]Cl 2 } was prepared and fully characterized as a new nano-Schif base complex. Nano-[Co-4CSP]Cl 2 was successfully used as an efcient catalyst for the synthesis of some 4H-pyrimido[2,1-b]benzazoles such as 4H-pyrimido[2,1-b]benzothiazoles and 4H-pyrimido[2,1-b]benzimidazoles. Keywords Nano-[Co-4CSP]Cl 2  · Pyrano[2,3-d]pyrimidine dione · 4H-pyrimido[2,1-b]benzazole · Schif base Introduction 4H-pyrimido[2,1-b]benzazole derivatives such as 4H-pyrimido[2,1-b]benzothia- zoles and 4H-pyrimido[2,1-b]benzimidazoles are important biological fused hetero- cyclic compounds which are prepared by the multi-component Biginelli-type reac- tion [1]. In this kind reaction, Biginelli-like compounds such as 4H-pyrimido[2,1-b] benzazoles were prepared by the condensation reaction of ethyl acetoacetate with various aldehyde and 2-aminobenzothiazole or 2-aminobenzimidazole, like thio- urea or urea in Biginelli reaction, to prepare 4H-pyrimido[2,1-b]benzothiazoles and 4H-pyrimido[2,1-b]benzimidazoles, respectively [1]. This condensation as a multi-component reaction through the direct synthesis of target product, without the Electronic supplementary material The online version of this article (https://doi.org/10.1007/s1116 4-020-04279-5) contains supplementary material, which is available to authorized users. * Ahmad Reza Moosavi-Zare moosavizare@yahoo.com * Hamid Goudarziafshar hamid_gafshar@yahoo.com 1 Sayyed Jamaleddin Asadabadi University, Asadabad 6541861841, Islamic Republic of Iran