Lithium amide → 2,2,6,6-Tetramethylpiperidin-4-yl 3-(5-Phenylsulfonylbenzotriazol-2-yl)-5-tert-butyl-4-hydroxyhydrocinnamate

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Reaction Conditions

Reaction Steps

Methyl 3-(5-phenylsulfonylbenzotriazol-2-yl)-5-tert-butyl-4-hydroxyhydrocinnamate (10 g, 0.02 mol), xylenes (100 g, 0.93 mol) and 2,2,6,6-tetramethyl-4-hydroxypiperidine (4.0 g, 0.025 mol) are charged to a reactor. The contents are heated to reflux in order to dry the xylenes. The contents are cooled to 50° C. at which time lithium amide (0.4 g, 0.017 mol) is added. The reaction mass is then heated to reflux and held at that temperature for 3.5 hours. The reaction is monitored by thin layer chromatography. The reaction mass is cooled to 50° C. and washed thrice with 100 g of water. The xylene is removed by distillation under vacuum to give 12.8 g of an orange oil which is subjected to silica gel chromatography for purification using ethyl acetate as the eluent. The title compound is obtained in a yield of 9.6 g (77%) as a yellow semi-solid, melting at 85-125° C., whole structure is confirmed by mass spectrometry and 1Hnmr.

Provenance & Evidence