(1-chloro-1-oxopropan-2-yl) acetate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: 5-Amino-3-acetoxymethyl-N-(2,3-diacetoxypropyl)-2,4,6-triiodobenzamide (3.20 g, 4.3 mmol) was dissolved in dry dimethylacetamide (4 ml). 2-Acetoxypropionyl chloride (2.17 ml, 17.2 mmol) was then added dropwise with efficient stirring. Stirring was continued over night. After work up according to the procedure in Example 24i, 3.66 g (100%) of product was isolated. was continued over night

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

Procedure: 2-(2-Methyl-7,8-dihydro-6H-indeno[5,4-d][1,3]oxazol-8-yl)ethanamine hydrochloride (150 mg, 0.593 mmol) and triethylamine (166 μL, 1.19 mmol) were dissolved in tetrahydrofuran (5 mL), 2-chloro-1-methyl-2-oxoethyl acetate (108 mg, 0.712 mmol) was added, and the mixture was stirred at room temperature for 30 min. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate/hexane=70/30→100/0) to give the title compound (78.4 mg, yield 40%). The solvent was evaporated under reduced pressure the residue was purified by silica gel column chromatography (ethyl acetate/hexane=70/30→100/0)

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

Procedure: Add dropwise a solution of 1-chloro-1-oxopropan-2-yl acetate (600 g, 3.98 mol) in toluene (1200 mL) to a solution of 1-cyclopent-1-enyl-pyrrolidine (546.7 g, 3.98 mol) and triethyl amine (483.9 g, 4.78 mol) in toluene (2400 mL). Reflux the mixture for overnight. Filter the mixture and concentrate the filtration to give crude 1-oxo-1-(2-(pyrrolidin-1-yl)cyclopent-1-enyl)propan-2-yl acetate (952 g), which is used in next step without further purification. 1H NMR (CDCl3, 400 MHz): δ 5.27 (m, 1H), 3.56 (m, 2H), 3.16 (m, 2H), 2.83 (m, 1H), 2.58 (m, 3H), 2.10 (s, 3H), 1.93 (m, 2H), 1.82 (m, 4H), 1.36 (d, J=7.2, 3H). Reflux the mixture for overnight Filter the mixture concentrate the filtration

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

Procedure: Stir a mixture of 2-acetoxy-propionic acid (550 g, 4.16 mol) in oxalyl chloride (500 mL) at room temperature for overnight. After removal of oxalyl chloride under vacuum, ˜700 g crude product is obtained (quantitative yield crude), which is used directly in the next step. 1H NMR (CDCl3, 400 MHz): δ 5.16 (m, 1H), 2.13 (s, 3H), 1.58 (d, J=7.2, 3H). After removal of oxalyl chloride under vacuum

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: Add dropwise a solution of 1-chloro-1-oxopropan-2-yl acetate (600 g, 3.98 mol) in toluene (1200 mL) to a solution of 1-cyclopent-1-enyl-pyrrolidine (546.7 g, 3.98 mol) and triethyl amine (483.9 g, 4.78 mol) in toluene (2400 mL). Reflux the mixture for overnight. Filter the mixture and concentrate the filtration to give crude 1-oxo-1-(2-(pyrrolidin-1-yl)cyclopent-1-enyl)propan-2-yl acetate (952 g), which is used in next step without further purification. 1H NMR (CDCl3, 400 MHz): δ 5.27 (m, 1H), 3.56 (m, 2H), 3.16 (m, 2H), 2.83 (m, 1H), 2.58 (m, 3H), 2.10 (s, 3H), 1.93 (m, 2H), 1.82 (m, 4H), 1.36 (d, J=7.2, 3H). Reflux the mixture for overnight Filter the mixture concentrate the filtration