Tetrahydrofuran → tert-Butyl 2-thioureidoacetate

Participants

Reaction Steps

To a 50 ml round bottom flask equipped with magnetic stirring bar was added a solvent mixture (10 ml THF, 5 ml of CHCl3, and 5 ml of DMF) and 168 mg (1 mmole) of glycine t-butyl ester hydrochloride. The solution was cooled by an ice-water bath and 415 ml (3 mmoles) of triethylamine was added. To the above mixture was added FITC (fluorescein isothiocyanate, 1 mmole, 385 mg) in small portions over 3 hours. The reaction mixture was allowed to stir overnight and then concentrated to a red-brown oil that was dissolved in 100 ml ethyl acetate and washed with 5 ml water followed by 2-10 ml portions of saturated brine. Preparative tlc on silica with 10% methanol in chloroform and a trace of acetic acid gave tlc pure material, 240 mg. Molar extinction coefficient: ε=79,500 M- cm-1 (λmax=494 nm) in 0.5M sodium carbonate, pH 9.53. Anal. calc for C27H24N2O7S·H2O: C, 60.22; H, 4.83; N, 5.20; S, 5.95. Found: C, 60.16; H, 4.85; N, 5.01; S, 6.15.

Provenance & Evidence