tert-butyl N-(3-bromo-2-fluoropropyl)carbamate

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:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a mixture of 2-benzyl-3-methyl-2,5,7,8,9,10-hexahydro-4H-benzo[g]pyrazolo[4,3-c]quinolin-4-one (1-7) (8.0 g, 23 mmol, 1 equiv) and cesium carbonate (37 g, 110 mmol, 4.9 equiv) in DMF (100 mL) was added tert-butyl 3-bromo-2-fluoropropylcarbamate (1-9) (7.1 g, 27.7 mmol, 1.2 equiv) and the resulting mixture was stirred at 40° C. for 16 h. The reaction mixture was filtered and the filtrate concentrated and purified by silica gel chromatography (100% hexanes to 100% ethyl acetate over 1 h) to yield tert-butyl 3-(2-benzyl-3-methyl-4-oxo-2,4,7,8,9,10-hexahydro-5H-benzo[g]pyrazolo[4,3-c]quinolin-5-yl)-2-fluoropropylcarbamate (1-10) as a white solid. LRMS m/z (M+H) 519.2 found, 519.3 required. The reaction mixture was filtered the filtrate concentrated purified by silica gel chromatography (100% hexanes to 100% ethyl acetate over 1 h)

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

Procedure: To a suspension of NBS (20 g, 110 mmol, 3.0 equiv) in dichloromethane (250 mL) was added dropwise triphenylphosphine (28 g, 110 nmol, 3.0 equiv) in dichloromethane (100 mL). After addition was complete, the reaction mixture was stirred for 10 min and a solution of tert-butyl 2-fluoro-3-hydroxypropylcarbamate (1-8) (7.0 g, 36 mmol, 1 equiv) in dichloromethane (100 mL) followed by pyridine (3.5 g, 44 mmol, 1.2 equiv) were added. The resulting mixture was stirred at 23° C. under nitrogen for 16 h. The reaction solution was concentrated and purified by silica gel chromatography (100% hexanes to 100% ethyl acetate over 1 h, analysis by Ninhydrin stain) to yield tert-butyl 3-bromo-2-fluoropropylcarbamate (1-9) as a clear oil. 1H NMR (500 MHz, CDCl3) δ 4.89-4.68 (m, 2H), 3.55-3.40 (m, 2H), 1.45 (s, 9H). After addition were added The resulting mixture was stirred at 23° C. under nitrogen for 16 h The reaction solution was concentrated purified by silica gel chromatography (100% hexanes to 100% ethyl acetate over 1 h, analysis by Ninhydrin stain)