methyl 4-fluorobenzoate

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

Procedure: A mixture of 1.2 parts of 1-chloro-1-fluoro-4-carbomethoxy-cyclohexane and 4.8 parts of o-dichlorobenzene were added to a bed of 2% palladium on carbon maintained at 300° C. A stream of nitrogen at 400 cc/min. swept the products into two cold traps at 0° C. and -80° C. to yield 3.84 parts of combined products. Analysis by gas chromatography and mass spectrometry indicated complete reaction to yield 85% 1-fluoro-4-carbomethoxy-cyclohexane, 5% 1-chloro-4-carbomethoxy-cyclohexane and 10% methyl-4-fluorobenzoate, excluding the solvent. at 0° C. -80° C. to yield 3.84 parts of combined products reaction

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

Procedure: 9.27 g KOtBu was added to 109 mg 18-Krone-6 and 5 mL 4-fluoracetophenone in 150 mL THF. After 30 min at RT 10.7 g 4-fluoro-benzoic acid methyl ester was added and stirred for 3 h at RT. The reaction was decomposed with water and filtered, the filtrate was concentrated and the residue was purified by chromatography on silica gel (cyclohexane/EE: 98:2). The solvent was removed and 3.9 g of the desired compound was obtained. (M+H)+: 261. filtered the filtrate was concentrated the residue was purified by chromatography on silica gel (cyclohexane/EE: 98:2) The solvent was removed

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of imidazole (132 g, 1.9 mol), methyl 4-fluorobenzoate (170 ml, 1.3 mol) and potassium carbonate (357 g, 2.6 mol) in DMSO (200 ml) is stirred at 120° C. for 3 h. After cooling to room temperature, the mixture is added to ice-water. Precipitated product is filtered off and washed with water. Yield: 59%. After cooling to room temperature Precipitated product is filtered off washed with water

Conditions: temp:135.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-hydroxypyridine (6.17 g, 64.87 mmol) was dissolved in 100 mL of anhydrous DMF under argon atmosphere. Solid K2CO3 (8.96 g, 64.87 mmol) was added, followed by neat methyl 4-fluorobenzoate (10.0 g, 64.87 mmol). The reaction mixture was heated at 135° C. for 10 hrs. The absence of the starting material was confirmed by LC/MS. The reaction mixture was cooled down to ambient temperature and poured into ca. 500 mL of H2O. The resulting solution was extracted 3 times with ca. 150 mL of EtOAc (during the extraction small volumes of MeOH, Et2O and brine were added to facilitate the separation). Combined EtOAc layers were washed twice with sat. NaHCO3, twice with brine and dried over anhydrous Na2SO4. Solvent was removed in vacuo to give dark-red oil, which was purified by silica gel chromatography using 1:1 mixture of EtOAc/Hexane as eluent to give the title product (4.8 g, 32.3% yield) as yellow solid. The reaction mixture was cooled down to ambient temperature The resulting solution was extracted 3 times with ca. 150 mL of EtOAc (during the extraction small volumes of MeOH, Et2O and brine were added the separation) Combined EtOAc layers were washed twice with sat. NaHCO3, twice with brine dried over anhydrous Na2SO4 Solvent was removed in vacuo to give dark-red oil, which was purified by silica gel chromatography 1:1 mixture of EtOAc/Hexane as eluent

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of methyl 4-fluorobenzoate (Lancaster 14154; 500 mg; 3.24 mmol; 1 eq.) and piperidine (Fluka 80640; 828.62 mg; 9.73 mmol; 3 eq.) in DMF (2 mL) was stirred at 50° C. for 16 hours. The reaction mixture was then passed through a short pad of silica and the obtained solution evaporated in vacuo to give a colourless oil. The oil was taken up in THF (15 mL) and lithium hydroxide (388.41 mg; 16.22 mmol; 5 eq.) was added followed by water (15 mL). The reaction mixture was stirred at room temperature for 6 hours then at 60° C. for 16 hours. NaOH (155.5 mg, 6.48 mmol, 2 eq) was then added and the reaction mixture was refluxed for 24 hours. After cooling, the solution was diluted with water and washed with Et2O. The aqueous layer was then acidified to pH 5-6 with acetic acid and the formed precipitate was collected by filtration, washed with water and dried under high vacuum to afford the title compound as a white solid. the obtained solution evaporated in vacuo to give a colourless oil The reaction mixture was stirred at room temperature for 6 hours at 60° C. for 16 hours the reaction mixture was refluxed for 24 hours After cooling washed with Et2O the formed precipitate was collected by filtration washed with water dried under high vacuum

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

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

Procedure: A solution of 9.84 grams of methyl 4-fluorobenzoate (63.9 mmol) and 12.40 grams of 4-(2-hydroxyethyl)piperdine (96 mmol) in 50 mL N-methylpyrrolidin-2-one was heated to 110°-120° C. and stirred for 72 hours. The dark solution was cooled and poured into 400 mL water. The tan precipitate was filtered off and washed well with water to yield 11.89 grams of crude product as a tan powder (71%). The crude material was recrystallized once from 100 mL ethanol which gave 4.75 grams (40% recovery) of a tan powder. Melting point 110°-115° C. 2H NMR δ (acetone-d6): 1.27 (2H, quad of doub, J=3.8 hz & 12.2 hz); 1.47 (2H, quad, J=6.6 hz); 1.71 (1H, mult); 1.80 (2H, br doub); 2.83 (2H, trip of doub, J=2.5 hz & 12.6 hz); 3.62 (2H, trip, J=6.6 hz); 3.78 (3H, s); 3.92 (2H, br doub); 6.93 (2H, doub); 7.81 (2H, doub). 13C NMR δ (acetone-d6): 32.59, 33.36, 40.30, 48.61, 51.55, 59.81, 114.30, 119.26, 132.0, 155.29, 167.18. The dark solution was cooled The tan precipitate was filtered off washed well with water