Trifluoroacetate → HCID 17964995, compound

Participants

Reaction Steps

(2R, 3S) (2-methyl-4-oxo-tetrahydrofuran-3-yl)-carbamic acid 9H-fluoren-9-ylmethyl ester (6b) (354 mg, 1.05 mmol, 1 eq) was dissolved in a mixture of ethanol (9.6 mL) and water (1.4 mL) containing sodium acetate.trihydrate (218 mg, 1.6 mmol, 1.5 eq). 4-[[(hydrazinocarbonyl)amino] methyl]cyclohexanecarboxylic acid. trifluoroacetate (346 mg, 1.05 mmol, 1 eq, Murphy, A. M. et al, J. Am. Chem. Soc., 114, 3156–3157, 1992) was added and the mixture refluxed for 2 hr. Chloroform (100 mL) was added and the organics washed with dilute aqueous hydrochloric acid (0.1 M, 1×100 mL). The acidic layer was backwashed with chloroform (3×100 mL) and the combined organics washed with brine (100 mL), dried (Na2SO4) and evaporated under reduced pressure to afford linker construct (8b) as a white solid (660 mg). Analytical HPLC indicated one main peak at Rt=17.011 min, HPLC-MS (main UV peak with Rt=7.96 min, 535.3 [M+H]+. Crude (8b) was used directly for construct loading.

Provenance & Evidence