Acetic Acid → HCID 69141315, compound

Participants

Reaction Conditions

Reaction Steps

(R)-2-Ethyl-piperazine-1,4-dicarboxylic acid 4-tert-butyl ester 1-(2-fluoro-5-iodo-benzyl) ester (8.9 g, 18 mM) was dissolved in tetrahydrofuran (150 mL), trisopropylborate (6.7 g, 36 mM) was added and the mixture was cooled to −78° C. At this low temperature n-butyllithium (16.9 mL, 1.6N) was added drop by drop with stirring. The mixture was stirred for 45 min at −78° C., for another 45 min at −50° C. and for 15 min at 0° C. Acetic acid (9.5 mL, 50%) was added slowly with stirring (0–5° C.), followed by hydrogen peroxide (2.75 mL, 35%). Stirring continued with cooling for another 45 min and for 1 h at room temperature. The mixture was partitioned between water and diethylether, organic phases were pooled, washed with water, sodium thiosulfate solution (5%), brine and dried with Na2SO4 to yield after evaporation a light yellow oil (8.5 g). This residue was purified by column chromatography (silica gel; n-hexane/ethylacetate 1:1) to yield 3.0 g (43%) of the product as a yellowish oil. MS (ISP): 400.5 (M+NH4)+.

Provenance & Evidence