A Simplified Protocol for Large-Scale Preparation of 4CzIPN and 3DPA2FBN

Abstract

Just in the past few years, the application of 4CzIPN as a photocatalyst in photochemistry has been dramatically increased with its unique properties. In the literature, a variety of protocols for the synthesis of 4CzIPN have been reported. However, a practical process for the preparation of 4CzIPN with consistent quality on large scale is not available, but highly desirable to enable the robust application of this photocatalysis in industry. Herein, we detailed a practical and simple column-free chemical process amenable for the large-scale production of 4CzIPN with high quality in 91% yield. Current process was demonstrated on large scale. The similar process protocol was applicable and demonstrated for the synthesis of 3DPA2FBN on large scale.

Key words

4CzIPN - 3DPA2FBN - photocatalyst - photochemistry - photocatalysis - kilogram - column-free

• References and Notes

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• 13 Our representative procedure for preparation of 3DPA2FBN (6) is described below. Under nitrogen, NaH (60 wt% in mineral oil, 221.42 g, 5535.4 mmol, 3.75 equiv) was charged into a clean and dry reactor. After THF (1800 mL) was added, the mixture was heated to 50 °C. Diphenylamine (879.4 g, 5092.6 mmol, 3.45 equiv) in THF (1200 mL) was slowly added while maintaining the internal temperature below 55 °C. The mixture was aged for 30 min at 50–55 °C before it was cooled to 23 °C. Pentafluorobenzonitrile (300 g, 1476.1 mmol, 1.0 equiv) was slowly added below 30 °C. After 16 h at 23 °C, the reaction was carefully quenched with water (450 mL). The solvent THF was then switched to water (2500 mL). The solid was collected and then washed with water (1200 mL). The crude product was then dried overnight under vacuum at 50 °C. The crude product was charged into a clean and dry reactor followed by addition of THF (2837 mL). The mixture was agitated for 1 h at 60 °C. After the mixture was cooled to 23 °C, the solid was collected by filtration and then washed with THF (2837 mL). After being dried under vacuum, the product 3DPA2FBN (6, 1086.1 g, 92.9 wt% by NMR) was isolated as a bright yellow solid with 95.2% yield. The NMR spectroscopic data were in accordance with the literature.¹¹
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