Phase Transfer Catalyzed Aromatic Nucleophilic Substituticn of Triflate Esters of 2-and 4-Nitro-estrone

Steroidal Estrogens

“…Nucleophilic exchange of the phenol trifiate ester is possible in a limited number of cases (SPYRIOUNIS et al 1990). Palladium(O)-complex catalysis has considerably broadened the repertoire of exchanging the phenolic OH group versus carbon functionality as exemplified by the transformation of estrone-3-trifiate (44) to the 3-carboxy derivative (45) (CACCHI et al1986;CACCHI and LUPI 1992;KUNZER and THIEL 1988b Being an essential element of the estradiol pharmacophore, the phenolic OH function has often been used to change pharmacodynamic characteristics or transport properties by creating oxygen linkages to form carboxylic esters, sulfates , sulfamates (HOWARTH et al 1994;SCHWARZ et al 1996), phosphonates (HOWARTH et al 1993), glycosides (HARREUS and KUNZ 1986) and glucuronides (OKHUBO et al1990).…”

Tris[2-(2-methoxyethoxy)ethyl]amine

“…Estrone triflate (28), when subjected to potassium thioacetate and TDA-1 in toluene at room temperature, gave 29 in 56% yield (eq 10). 12 Finally, aryl fluorides and chlorides bearing an electron-withdrawing group undergo the S N Ar reaction with trifluoroethanol at elevated temperatures (100-147 • C) in the presence of NaOH and 5-10 mol % TDA-1 to give the corresponding trifluoroethyl ethers (36-82% yield). 13 The reaction was also performed using NaH and DMF at 45-75 • C. However, the authors stated that the ease of work-up and isolation with the solid-liquid two-phase system were tremendous advantages.…”