Efficient synthesis of 2,2’-bis(2-oxazoline) from dimethyl oxalate

Abstract In view of the problems in the synthesis of 2,2’-bis(2-oxazoline) (BOZ), such as high cost of raw materials, long reaction time, low yield and complex purification, BOZ was synthesized from dimethyl oxalate (DMO) and ethanolamine (MEA) via a three-step method. The optimum conditions were as follows: First, in ethanol, DMO and MEA reacted at molar ratio of 1∶2.6 at 40 ℃ for 20 min to obtain N,N-bis(2-hydroxyethyl) acetamide (BHEOA). Then in toluene, BHEOA and SOCl₂ reacted at molar ratio of 1∶3 at 50 to 90 ℃ to obtain N,N-bis(chloroethyl) acetamide (BCEOA). Finally, in ethanol containing water absorbent, BCEOA and NaOH reacted at molar ratio of 1∶2 at reflux temperature for 1 h to obtain BOZ. The yields of the three steps were 98.1%, 96.3% and 73.6% respectively. After secondary crystallization of the filtrate in the third step, the yield increased to 85.8%.

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	GE Haodong
	WU Linbo

Keywords： chain extender 2,2’-bis(2-oxazoline) dimethyl oxalate

Received 2023-03-13;

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GE Haodong, WU Linbo.Efficient synthesis of 2,2’-bis(2-oxazoline) from dimethyl oxalate[J] Chemcial Industry and Engineering, 2025,V42(1): 9-18

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