3-[(2-methylpropan-2-yl)oxycarbonyl]-1,1-dioxo-1,3-thiazolidine-4-carboxylic acid

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

Procedure: Carbonyldiimidazole (520 mg, 3.21 mmol) was added to an ice cold solution of 3-tert-butoxycarbonyl-1,1-dioxo-1,3-thiazolidine-4-carboxylic acid (Example 127 b, 304 mg, 1.15 mmol) in DMF (1 mL). After 5 min. the mixture was warmed to ambient temperature and stirred for 2 h. Gaseous NH3 was bubbled for 10 min through the solution while the temperature was kept below 20° C. Stirring was continued for 12 h at ambient temperature. The reaction mixture was poured into 30 mL ice/water/1N HCl and extracted with EtOAc (2×30 mL). The combined extracts were washed with ice/brine (20 mL), dried over Na2SO4 and concentrated in vacuo to give the title compound (197 mg, 65%) as white solid, MS (ESI) m/e=263.1 [M−H−]. Gaseous NH3 was bubbled for 10 min through the solution while the temperature was kept below 20° C Stirring was continued for 12 h at ambient temperature The reaction mixture was poured into 30 mL ice/water/1N HCl extracted with EtOAc (2×30 mL) The combined extracts were washed with ice/brine (20 mL) dried over Na2SO4 concentrated in vacuo

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

Procedure: Carbonyldiimidazole (520 mg, 3.21 mmol) was added to an ice cold solution of 3-tert-butoxycarbonyl-1,1-dioxo-1,3-thiazolidine-4-carboxylic acid (Example 127 b, 304 mg, 1.15 mmol) in DMF (1 mL). After 5 min. the mixture was warmed to ambient temperature and stirred for 2 h. Gaseous NH3 was bubbled for 10 min through the solution while the temperature was kept below 20° C. Stirring was continued for 12 h at ambient temperature. The reaction mixture was poured into 30 mL ice/water/1N HCl and extracted with EtOAc (2×30 mL). The combined extracts were washed with ice/brine (20 mL), dried over Na2SO4 and concentrated in vacuo to give the title compound (197 mg, 65%) as white solid, MS (ESI) m/e=263.1 [M−H−]. Gaseous NH3 was bubbled for 10 min through the solution while the temperature was kept below 20° C Stirring was continued for 12 h at ambient temperature The reaction mixture was poured into 30 mL ice/water/1N HCl extracted with EtOAc (2×30 mL) The combined extracts were washed with ice/brine (20 mL) dried over Na2SO4 concentrated in vacuo

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

Procedure: A solution of O3-tert-butyl O4-methyl 1,1-dioxo-1,3-thiazolidine-3,4-dicarboxylate (Example 127 a, 0.35 g, 1.25 mmol) and lithium hydroxide hydrate (63.1 mg, 1.5 mmol) in THF (3.5 mL) and water (1.05 mL) was stirred for 20 h at ambient temperature. The reaction mixture was poured onto ice/0.1N HCl (25 mL) and extracted with EtOAc (2×25 mL). The combined extracts were washed with ice/brine (1×25 mL), dried over Na2SO4 and filtered. The solvent was removed under reduced pressure to give the title compound (306 mg, 92%) as colorless foam, MS (ESI) m/e=264.05 [M−H−]. The reaction mixture was poured onto ice/0.1N HCl (25 mL) extracted with EtOAc (2×25 mL) The combined extracts were washed with ice/brine (1×25 mL) dried over Na2SO4 filtered The solvent was removed under reduced pressure

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

Procedure: Carbonyldiimidazole (520 mg, 3.21 mmol) was added to an ice cold solution of 3-tert-butoxycarbonyl-1,1-dioxo-1,3-thiazolidine-4-carboxylic acid (Example 127 b, 304 mg, 1.15 mmol) in DMF (1 mL). After 5 min. the mixture was warmed to ambient temperature and stirred for 2 h. Gaseous NH3 was bubbled for 10 min through the solution while the temperature was kept below 20° C. Stirring was continued for 12 h at ambient temperature. The reaction mixture was poured into 30 mL ice/water/1N HCl and extracted with EtOAc (2×30 mL). The combined extracts were washed with ice/brine (20 mL), dried over Na2SO4 and concentrated in vacuo to give the title compound (197 mg, 65%) as white solid, MS (ESI) m/e=263.1 [M−H−]. Gaseous NH3 was bubbled for 10 min through the solution while the temperature was kept below 20° C Stirring was continued for 12 h at ambient temperature The reaction mixture was poured into 30 mL ice/water/1N HCl extracted with EtOAc (2×30 mL) The combined extracts were washed with ice/brine (20 mL) dried over Na2SO4 concentrated in vacuo

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

Procedure: A solution of O3-tert-butyl O4-methyl 1,1-dioxo-1,3-thiazolidine-3,4-dicarboxylate (Example 127 a, 0.35 g, 1.25 mmol) and lithium hydroxide hydrate (63.1 mg, 1.5 mmol) in THF (3.5 mL) and water (1.05 mL) was stirred for 20 h at ambient temperature. The reaction mixture was poured onto ice/0.1N HCl (25 mL) and extracted with EtOAc (2×25 mL). The combined extracts were washed with ice/brine (1×25 mL), dried over Na2SO4 and filtered. The solvent was removed under reduced pressure to give the title compound (306 mg, 92%) as colorless foam, MS (ESI) m/e=264.05 [M−H−]. The reaction mixture was poured onto ice/0.1N HCl (25 mL) extracted with EtOAc (2×25 mL) The combined extracts were washed with ice/brine (1×25 mL) dried over Na2SO4 filtered The solvent was removed under reduced pressure