Hydrochloric Acid → 4-(2,6-Dimethyl-4-nitrophenoxy)-2-(4-fluorobenzenesulfonyl)phenol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 2-(4-fluoro-benzenesulfonyl)-benzene-1,4-diol (10.0 g, 37.3 mmol) in dry 1-methyl-2-pyrrolidinone (100 mL) with 3 A molecular sieves (3.0 g) was sparged with dry nitrogen for 15 min at RT. The solution was cooled to 0° C. and potassium bis(trimethylsilyl)amide (18.59 g, 93.2 mmol) was added in a single portion to give a deep red suspension. The suspension was warmed to RT with continued sparging. 18-Crown-6 (10.8 g, 41.0 mmol) was added in a single portion and the solution was cooled to 0° C. To the cooled suspension was added 2-chloro-1,3-dimethyl-5-nitro-benzene (8.30 g, 44.7 mmol) to give a brown solution and sparging was ceased. The solution warmed to RT and stirred under dry nitrogen for 3 h. The crude reaction mixture was poured into 1M HCl (1 L) at 0° C. and extracted with EtOAc (3×300 mL). Combined extracts were washed with 1M HCl (4×1 L) and brine (1 L), dried over anhydrous sodium sulfate, treated with activated carbon and filtered. The filtrate was concentrated to a tan solid which was filtered through silica gel (150 g) with 1:9:10 methanol:hexanes:CH2Cl2 (1.5 L). Concentration of the filtrate gave the title compound of Step C as a tan solid (11.4 g). The title product of Step C was used in the next step without further purification. MS (APCl−) Calc.: 417.1. Found: 416.0 (M−1).

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