Tetrabutylammonium Fluoride → HCID 54535988, compound

Participants

Reaction Steps

The operation is carried out in a fashion similar to that described in Example 41, but starting from 2.0 g of 2-trimethylsilylethyl (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-chlorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoate and 6.5 cm3 of 1M tetrabutylammonium fluoride solution. The crude product is purified by chromatography on silica [eluent: ethyl 0.65 g of acetate/methanol (90/10 by volume)]. The fractions containing the expected product are combined and concentrated to dryness under reduced pressure at 40° C. After vigorous stirring in diisopropyl ether, 0.65 g of (2R,4R)-3-{3-{2-[4-tert-butoxycarbonyl-2-(2-chlorophenyl)-3-thiazolidinyl]-2-oxoethyl}ureido}benzoic acid is thus obtained in the form of an amorphous solid ([α]D20 =+88°±2° (C=0.39%; CHCl3)) [proton NMR (200 MHz, DMSO D6, δ in ppm), 2 rotamers at room temperature, peak coalescence at 120° C., characteristic chemical shifts at 120° C.: 7.3 to 7.6 (m, 7H, aromatic); 7.95 (bs, 1H, N--C6H4 -- in position 2). Infrared spectrum (KBr), characteristic bands in cm-1 : 3390, 2985, 2940, 2600, 1735, 1660, 1610, 1560, 1375, 1240, 1155, 755, 685].

Provenance & Evidence