Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → 2-(3-Cyclopentyloxy-4-methoxybenzyl)-4-hydroxybenzoxazole

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Reaction Steps

A solution of N-(2,6-dihydroxyphenyl)-3-cyclopentyloxy-4-methoxyphenylacetamide (2.10 g) and pyridinium p-toluene-sulphonate (532 mg) in xylene (100 ml) was refluxed, under nitrogen, overnight. The reaction mixture was cooled to room temperature, diluted with water (100 ml), and extracted with dichloromethane (3×75 ml). The combined organic extracts were washed with water (3×100 ml), brine (100 ml), dried (CaSO4) and evaporated in-vacuo to yield a pale brown solid. The solid was purified by flash chromatography (SiO2 ; dichloromethane;methanol (50:1)) to yield the title compound (1.027 g, 51%) as a white solid (mp 172°-181° C.). δH (250MHz;d6DMSO) 1.53-1.85 (8H,m,4×CH2), 3.70 (3H, s,OMe), 4.18 (2H,s,CH2), 4.72 (1H,m,CH), 6.69 (1H,dd,ArH), 6.82 (1H,dd,ArH), 6.89 (1H,d,ArH), 6.93 (1H,d,ArH), 7.02 (1H,dd,ArH), 7.11 (1H,t,ArH), 10.22 (1H,s,ArOH). m/z 339 (M+), 271 (M--C5H8), 256,242,228,199,149,137,123,94.

Provenance & Evidence