1-Butanol → 4,7-bis(4-isopropoxyphenyl)-2-isobutyl-2H-benzo[d][1,2,3]triazole

Participants

Reaction Conditions

Reaction Steps

A mixture of Intermediate K (666 mg, 2.0 mmol), 4-isopropoxyphenylboronic acid (1.00 g, 5.5 mmol), tetrakis(triphenylphosphine)palladium(0) (0.50 g, 0.43 mmol), solution of sodium carbonate (1.06 g, 10 mmol) in water (8 mL), butanol (30 mL), and toluene (20 mL) was vigorously stirred and heated under argon at 100° C. for 20 hours. The reaction mixture was poured into water (300 mL), stirred for 30 minutes and extracted with toluene/ethyl acetate (1:1, 300 mL). The volatiles were removed under reduced pressure, and the residue was chromatographed (silica gel, hexane/dichloromethane, 1:1). The separated product was recrystallized from ethanol to give pure 4,7-bis(4-isopropoxyphenyl)-2-isobutyl-2H-benzo[d][1,2,3]triazole, Compound 43 (655 mg, 74% yield). 1H NMR (400 MHz, CDCl3): δ 8.00 (d, J=8.7 Hz, 4H, 4-i-PrOC6H4), 7.55 (s, 2H, benzotriazole), 7.02 (d, J=8.8 Hz, 4H, 4-i-PrOC6H4), 4.64 (septet, J=6.2 Hz, 2H, 4-i-PrOC6H4), 4.59 (d, J=7.7 Hz, 2H, i-Bu), 2.61 (m, 1H, i-Bu), 1.38 (d, J=6.2 Hz, 12H, 4-i-PrOC6H4), 1.01 (d, J=6.6 Hz, 6H, i-Bu). UV-vis spectrum (PVB): λmax=360 nm. Fluorimetry (PVB): λmax=435 nm.

Provenance & Evidence