tert-butyl 2-(carbamothioylamino)acetate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the crude product from Example 1 in anhydrous THF (200 mL) is added N,N-diisopropylethylamine (25 mL, 143 mmol) followed by 2-bromomalonaldehyde (18.5 g, 123 mmol). The resulting mixture is allowed to stir at room temperature for 18 h, heated to 70° C. for 6 h, and then stirred at room temperature for an additional 18 h. The solvent is removed in vacuo and the residue is partitioned between EtOAc (400 mL) and water (350 mL). The water layer is back extracted with EtOAC (300 mL), the organic layers are combined, washed with brine (1×200 mL), dried over Na2SO4, filtered and the solvent removed in vacuo. The residue is purified by BIOTAGE® Silica gel chromatography on a 300 g Thompson Single Step silica cartridge using a linear gradient from 100% CH2Cl2 to 45% EtOAc/CH2Cl2 over 8 column volumes to give 3.5 g (17%, 2 steps) of the title compound as a tan solid. LC/MS (Condition A): ret. T=2.66 min, (M+Na) 265.09. 1H NMR (500 MHz, chloroform-d) δ ppm 9.73 (1 H, s), 7.86 (1 H, s), 4.05 (2 H, s), 1.49 (9 H, s). heated to 70° C. for 6 h stirred at room temperature for an additional 18 h The solvent is removed in vacuo the residue is partitioned between EtOAc (400 mL) and water (350 mL) The water layer is back extracted with EtOAC (300 mL) washed with brine (1×200 mL) dried over Na2SO4 filtered the solvent removed in vacuo The residue is purified by BIOTAGE® Silica gel chromatography on a 300 g Thompson Single Step silica cartridge

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a magnetically stirred suspension of tert-butyl 2-aminoacetate (11.2 g, 85 mmol) in CH2Cl2 (200 mL) under nitrogen is added 1,1′-thiocarbonyldipyridin-2(1H)-one (21 g, 90 mmol) and the resulting mixture is stirred at room temp. for 18 h. The solvent is removed in vacuo, the residue treated with 2M ammonia in methanol (600 mL, 1200 mmol) and stirred at room temperature for 45 min. The solvent is removed in vacuo and dried under high vacuum to give the title compound as a reddish oil that is used “as is” without further purification in the next step. LC/MS (Condition A): ret. T=2.19 min, (M+H)+ 191—actually see (M−55) 134.95 (this is characteristic of BOC fragmentation pattern). The solvent is removed in vacuo stirred at room temperature for 45 min The solvent is removed in vacuo dried under high vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 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. To a 50 ml round bottom flask equipped with magnetic stirring bar The solution was cooled by an ice-water bath concentrated to a red-brown oil that was dissolved in 100 ml ethyl acetate washed with 5 ml water Preparative tlc on silica with 10% methanol in chloroform and a trace of acetic acid gave tlc pure material, 240 mg