Catalyst Free Synthesis of Pyridine-2,6-bis(2-bromo-propane-1,3-dione) and Pyrdine-2,6-bis(<i>N</i>-arylthiazoline-2-thiones)

Abstract

We have described herein a catalyst-free preparation method of pyridine-2,6-bis(N-alkylthiazoline-2-thiones) (4a-i) by the reaction of primary amines, CS 2 , and pyridine-2,6-bis(2-bromo-1,3dicarbonyl) derivatives (2a-c) in water. Also, we have described a catalyst free, green chemistry protocols to monobromination of pyridine-2,6-bis(2-bromo-1,3-dicarbonyl) derivatives with high yield, using NBS as a brominating agent, that led to eco-friendly isolation and purification procedures. Furthermore, we have studied the reactivity of pyridine-2,6-bis(2-bromo-1-methyl-propane-1,3-dione) (2a) towards thiourea to afford 2,6-bis(5-benzoyl-2-aminothiazol-4-yl)pyridine (9).

Mononuclear Fe(II) Complexes Based on the Methylpyrazinyl-Diamine Ligand: Chemical-, Thermo- and Photocontrol of Their Magnetic Switchability

“…After the reaction was complete (monitored by TLC), the mixture was separated by filtration and the filtrate was concentrated in vacuo giving crude product 2-(chloromethyl)pyrazine. 14 Then to a solution of 3.24 g (25.6 mmol) of 2-(chloromethyl)-pyrazine in 50 mL of tetrahydrofuran were added 1.1 g (12.2 mmol) of N,N′-dimethyl-ethylenediamine and 5.1 g (52.0 mmol) of trimethylamine. The mixture was stirred for 24 h at reflux, followed by addition of a 30 mL aqueous solution of 3 M NaOH.…”