Veratroyl chloride → HCID 135470462, compound

Participants

Reaction Steps

7-Amino-4-hydroxy-3-(4-methoxy-phenylazo-napthalene-2-sulfonic acid isopropyl ester (Example 6, 100 mg, 0.24 mmol ) was dissolved in dichloromethane (15 mL) and diisopropylethylamine (84 μL, 62 mg, 0.48 mmol). 3,4-Dimethoxybenzoyl chloride (56 mg, 0.28 mmol) was added under nitrogen and the reaction mixture was allowed to stir for 16 h. The solution was washed with water, 1N HCl, and saturated sodium bicarbonate solution. The organic layer was dried with MgSO4 and concentrated. This concentrate was purified by chromatography (silica gel, eluent: 50% ethyl acetate/hexane) to provide the sulfonic acid, isopropyl ester (27 mg, 0.047 mmole, 17%). This ester (16 mg, 0.028 mmole) was suspended in 2-butanone (0.5 mL) and sodium iodide (6 mg, 0.041 mmole) was added. The resulting suspension was heated with stirring to 60° C. for 72 h. The solvent was removed under a stream of nitrogen. The remaining solid was suspended in acetone and filtered to provide the title compound (9 mg, 0.016 mmole, 67%, calculated from the isopropyl ester) as a red solid: NMR (DMSO-d6): δ 16.30 (s, 1H), 10.39 (s, 1H), 8.26 (d, J=9 Hz, 1H), 8.17 (s, 1H), 7.96 (d, J=8 Hz, 1H), 7.90 (d, J=8 Hz, 2H), 7.68 (d, J=9 Hz, 1H), 7.58 (s, 1H), 7.50 (s, 1H), 7.10 (m, 3H), 3.95 (m, 9H): Analytical HPLC: 82% pure: MS (ES-NEG): [M−H] 536.

Provenance & Evidence