methyl 3-bromo-4-oxobutanoate

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

Procedure: N-(aminocarbonothioyl)-3-chloro-2-methylbenzenesulfonamide (0.4 g, 1.5 mmol) and methyl 3-bromo-4-oxobutanoate (0.3 g, 1.5 mmol), dissolved in pyridine (5 mL), were irradiated in a microwave oven for 2.5 min at 130° C. The solvent was removed under reduced pressure and the product separated from the starting materials using preparative HPLC (yield 0.2 g, 30%). were irradiated in a microwave oven for 2.5 min at 130° C The solvent was removed under reduced pressure the product separated from the starting materials

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

Procedure: N-(aminocarbonothioyl)-3-chloro-2-methylbenzenesulfonamide (0.4 g, 1.5 mmol) and methyl 3-bromo-4-oxobutanoate (0.3 g, 1.5 mmol), dissolved in pyridine (5 mL), were irradiated in a microwave oven for 2.5 min at 130° C. The solvent was removed under reduced pressure and the product separated from the starting materials using preparative HPLC (yield 0.2 g, 30%). were irradiated in a microwave oven for 2.5 min at 130° C The solvent was removed under reduced pressure the product separated from the starting materials

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

Procedure: N-(aminocarbonothioyl)-3-chloro-2-methylbenzenesulfonamide (0.4 g, 1.5 mmol) and methyl 3-bromo-4-oxobutanoate (0.3 g, 1.5 mmol), dissolved in pyridine (5 mL), were irradiated in a microwave oven for 2.5 min at 130° C. The solvent was removed under reduced pressure and the product separated from the starting materials using preparative HPLC (yield 0.2 g, 30%). were irradiated in a microwave oven for 2.5 min at 130° C The solvent was removed under reduced pressure the product separated from the starting materials

Conditions: temp:110.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 250-mL round bottom flask was charged with methyl 3-bromo-4-oxobutanoate (5.00 g, 25.6 mmol) and urea (2.08 g, 34.6 mmol) in DMF (15 mL) and heated to 110° C. for 30 minutes. After this time, the mixture was cooled to room temperature and concentrated under reduced pressure. The residue was absorbed onto silica and purified by chromatography on silica using dichloromethane/(89:9:1 dichloromethane/methane/conc. NH4OH) (10:0 to 0:10) as eluent, to afford the title compound (0.72 g, 18%) as a red oil. MW=156.14. 1H NMR (DMSO-d6, 300 MHz) δ 9.54 (s, 1H), 6.48 (s, 2H), 6.45 (s, 1H), 3.64 (s, 2H), 3.62 (s, 3H). After this time, the mixture was cooled to room temperature concentrated under reduced pressure The residue was absorbed onto silica purified by chromatography on silica

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

Procedure: A 500-mL round bottom flask was charged with methyl 4-oxobutanoate (8.52 g, 73.3 mmol), dioxane (0.7 mL) in diethyl ether (70 mL). Bromine (3.94 mL, 77.0 mmol) was added at room temperature over 1.5 h. After this time, the mixture was diluted with dichloromethane (250 mL) and solid sodium bicarbonate (13.6 g, 161 mmol) was added. After stirring for 2 h the mixture was filtered and the filtrate concentrated under reduced pressure to afford the title compound (15.3 g, 100%) as a colorless oil. MW=195.01. 1H NMR (CDCl3, 300 MHz) δ 9.54 (s, 1H), 4.68 (dd, J=6.9, 6.6 Hz, 1H), 3.74 (s, 3H), 3.25 (dd, J=17.4, 7.2 Hz, 1H), 2.94 (dd, J=17.1, 6.6 Hz, 1H). was added was filtered the filtrate concentrated under reduced pressure

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

Procedure: N-(aminocarbonothioyl)-3-chloro-2-methylbenzenesulfonamide (0.4 g, 1.5 mmol) and methyl 3-bromo-4-oxobutanoate (0.3 g, 1.5 mmol), dissolved in pyridine (5 mL), were irradiated in a microwave oven for 2.5 min at 130° C. The solvent was removed under reduced pressure and the product separated from the starting materials using preparative HPLC (yield 0.2 g, 30%). were irradiated in a microwave oven for 2.5 min at 130° C The solvent was removed under reduced pressure the product separated from the starting materials