4-Toluenesulfonyl chloride → Toluene-4-sulfonic acid 3-[4-(1-tert-butyl-5-chloro-6-oxo-1,6-dihydro-pyridazin-4-yloxymethyl)-phenyl]-1-methylpropyl ester

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Reaction Steps

To a solution of the product of Example 7B (200 mg, 0.548 mmol) in pyridine (10 mL) was added p-toluenesulfonyl chloride (209 mg, 1.096 mmol). The reaction was stirred at room temperature overnight under nitrogen atmosphere. Monitoring by LC-MS showed a 1:1 mixture of starting material and product. The reaction was diluted with ethyl acetate and washed with 5% CuSO4 until a light blue aqueous solution was maintained. The organic layer was then dried over Na2SO4, filtered, and concentrated. The crude material was purified by flash column chromatography (3:1 hexane:ethyl acetate to 100% ethyl acetate) to recover the starting material (90 mg) and the product as a clear oil (74 mg, 47% yield based on recovered starting material). 1H NMR (600 MHz, CDCl3): 7.80 (d, 2H, J=8.3 Hz), 7.72 (s, 1H), 7.33 (d, 2H, J=8.0 Hz), 7.30 (d, 2H, J=8.1 Hz), 7.13 (d, 2H, J=8.1 Hz), 5.27 (s, 2H), 4.66 (m, 1H), 2.65 (m, 1H), 2.54 (m, 1H), 2.45 (s, 3H), 1.94 (m, 1H), 1.81 (m, 1H), 1.63 (s, 9H), 1.26 (s, 3H).

Provenance & Evidence