2-(difluoromethoxy)benzaldehyde

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: 7.2 g of potassium cyanide were dissolved in 30 ml of water and 6 ml of ethanol, while cooling. 16 g of 2-difluoromethoxybenzaldehyde were then added at 0°-5° C., while cooling. After subsequently stirring the mixture between 0° and 10° C. for 20 minutes, a mixture of 7 ml of concentrated H2SO4 and 18 ml of water was added dropwise. The mixture was subsequently stirred for a further 2 hours and was thereby allowed to come to room temperature. After extracting twice with methylene chloride, the organic phase was dried and the solvent was distilled off. 2-Difluoromethoxy-α-cyano-benzyl alcohol was obtained as a colorless oil, the structure of which was confirmed by a nuclear magnetic resonance spectrum. The yield was virtually quantitative. while cooling was added dropwise The mixture was subsequently stirred for a further 2 hours to come to room temperature After extracting twice with methylene chloride the organic phase was dried the solvent was distilled off

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

Procedure: N′-(6-fluoro-pyridine-3-carbothioyl)-hydrazinecarboxylic acid tert-butyl ester (0.044 mmol) prepared as described in example 3 for N′-(4-fluoro-benzoyl)-hydrazinecarboxylic acid tert-butyl ester, is treated with TFA (0.44 mmol) and thioanisole (0.44 mmol) in dry CH2Cl2 (1 mL) at room temperature for 30 minutes. The solvent is removed and the residue is dissolved in dry CH2Cl2 (1 mL). DIEA (0.22 mmol) is added to the solution and the mixture is treated with 2-difluoromethoxy-benzaldehyde (0.067 mmol) in the presence of 4 Å molecular sieves. 2,4,6-Trifluorobenzoyl chloride (0.089 mmol) is added after 5 minutes. The mixture is kept at room temperature for 16 hours and purified by preparative silica gel TLC (30% EtOAc/hexane) to yield [2-(2-difluoromethoxy-phenyl)-5-(6-fluoro-pyridin-3-yl)-[1,3,4]thiadiazol-3-yl]-(2,4,6-trifluoro-phenyl)-methanone: 1H NMR (400 MHz, CDCl3) 8.39 (s, 1H), 7.93-7.97 (m, 1H), 7.54 (s, 1H), 7.37-7.41 (m, 2H), 7.24-7.27 (m, 1H), 7.19 (d, J=8.1 Hz, 1H), 6.97 (dd, J1=8.6 Hz, J2=2.7 Hz, 1H), 6.78 (t, J=8.3 Hz, 2H), 6.67 (dd, J1=75.0 Hz, J2=71.7 Hz, 1H); LC/MS (ES+): (M+1) 484.1. The solvent is removed the residue is dissolved in dry CH2Cl2 (1 mL) purified by preparative silica gel TLC (30% EtOAc/hexane)

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

Procedure: N′-(6-Methyl-pyridine-3-carbothioyl)-hydrazinecarboxylic acid tert-butyl ester (0.1 mmol) prepared as described in example 3 for N′-(4-fluoro-benzoyl)-hydrazinecarboxylic acid tert-butyl ester, is treated with TFA (1 mmol) in dry CH2Cl2 (1 mL) at room temperature for 30 minutes. Solvent is removed and the residue is dissolved in dry CH2Cl2 (1 mL). DIEA (0.287 mmol) is added to the solution and the mixture is treated with 2-difluoromethoxy-benzaldehyde (0.12 mmol) in the presence of 4 Å molecular sieves. 2,4,6-Trifluorobenzoyl chloride (0.15 mmol) is added after 5 minutes. The mixture is kept at ambient temperature for 16 hours and purified by preparative HPLC (20-100% MeCN/H2O) to yield [2-(2-difluoromethoxy-phenyl)-5-(6-methyl-pyridin-3-yl)-[1,3,4]thiadiazol-3-yl]-(2,4,6-trifluoro-phenyl)-methanone: 1H NMR (400 MHz, CDCl3) 8.71 (d, J=2.1 Hz, 1H), 7.81 (dd, J1=8.2 Hz, J2=2.2 Hz, 1H), 7.53 (s, 1H), 7.36-7.4 (m, 2H), 7.26 (d, J=8.1 Hz, 2H), 7.18 (d, J=8.3 Hz, 1H), 6.78 (t, J=8.3 Hz, 2H), 6.67 (dd, J1=75.0 Hz, J2=71.7 Hz, 1H), 2.64 (s, 3H); LC/MS (ES+): (M+1) 480.1. Solvent is removed the residue is dissolved in dry CH2Cl2 (1 mL) purified by preparative HPLC (20-100% MeCN/H2O)

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

Procedure: To a heterogeneous mixture of 4-chloro-thiobenzoic acid hydrazide (0.107 mmol) in CH2Cl2 (1 mL) is added 2-difluoromethoxy-benzaldehyde (0.128 mmol) and DIEA (0.128 mmol). After 10 minutes the mixture become homogenous and the reaction is complete by TLC and LCMS to give 5-(4-chloro-phenyl)-2-(2-difluoromethoxy-phenyl)-2,3-dihydro-[1,3,4]thiadiazole which is used in the next step without evaporation of the solvent.

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of 2-(difluoromethoxy)benzaldehyde (295 g, 1714 mmol) and ethyl (triphenylphosphoranylidene)pyruvate (279.1 g, 742 mmol) was heated at 100° C. The dark red aldehyde immediately decolorized, and a yellow suspension was obtained, which slowly changed to a dark brown solution. 2-(Difluoromethoxy)benzaldehyde (52.5 g, 305 mmol) was added to the reaction mixture. Residual aldehyde was separated from the reaction mixture by distillation. The resulting mixture was stirred in heptane (500 mL) and diethyl ether (500 mL). The brown solid precipitate was filtered off, and washed with a 1:1 mixture of heptane and diethyl ether (3×250 mL). The filtrate was concentrated, yielding a brown oil (218.5 g). Purification by flash column chromatography (1.5 kg silica, 2-20% EtOAc in heptane, 125 mL/minute) gave the title compound (91 g) as a yellow oil. δH (CDCl3, 300 MHz) 1.42 (t, J 7.1 Hz, 3H), 4.40 (q, J 7.1 Hz, 2H), 6.59 (t, J 72.9 Hz, 1H), 7.20 (dd, J 7.3, 1.0 Hz, 1H), 7.28 (br t, J 7.6 Hz, 1H), 7.38 (d, J 16.3 Hz, 1H), 7.46 (dt, J 7.8, 1.7 Hz, 1H), 7.75 (dt, J 7.8, 1.6 Hz, 1H), 8.13 (d, J 16.3 Hz, 1H). MS [ES+] m/z 271 [M+H]+. a yellow suspension was obtained Residual aldehyde was separated from the reaction mixture by distillation The brown solid precipitate was filtered off washed with a 1:1 mixture of heptane and diethyl ether (3×250 mL) The filtrate was concentrated

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of 2-(difluoromethoxy)benzaldehyde (295 g, 1714 mmol) and ethyl (triphenylphosphoranylidene)pyruvate (279.1 g, 742 mmol) was heated at 100° C. The dark red aldehyde immediately decolorized, and a yellow suspension was obtained, which slowly changed to a dark brown solution. 2-(Difluoromethoxy)benzaldehyde (52.5 g, 305 mmol) was added to the reaction mixture. Residual aldehyde was separated from the reaction mixture by distillation. The resulting mixture was stirred in heptane (500 mL) and diethyl ether (500 mL). The brown solid precipitate was filtered off, and washed with a 1:1 mixture of heptane and diethyl ether (3×250 mL). The filtrate was concentrated, yielding a brown oil (218.5 g). Purification by flash column chromatography (1.5 kg silica, 2-20% EtOAc in heptane, 125 mL/minute) gave the title compound (91 g) as a yellow oil. δH (CDCl3, 300 MHz) 1.42 (t, J 7.1 Hz, 3H), 4.40 (q, J 7.1 Hz, 2H), 6.59 (t, J 72.9 Hz, 1H), 7.20 (dd, J 7.3, 1.0 Hz, 1H), 7.28 (br t, J 7.6 Hz, 1H), 7.38 (d, J 16.3 Hz, 1H), 7.46 (dt, J 7.8, 1.7 Hz, 1H), 7.75 (dt, J 7.8, 1.6 Hz, 1H), 8.13 (d, J 16.3 Hz, 1H). MS [ES+] m/z 271 [M+H]+. a yellow suspension was obtained Residual aldehyde was separated from the reaction mixture by distillation The brown solid precipitate was filtered off washed with a 1:1 mixture of heptane and diethyl ether (3×250 mL) The filtrate was concentrated

Conditions: temp:-55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of p-toluenesulfonylmethyl isocyanide (2.4 g) in dimethoxyethane (10 mL) was added to a solution of potassium tert-butoxide (2.68 g) in dimethoxyethane (30 mL) at −35° C., and the reaction solution was stirred at the same temperature for 10 minutes. The reaction solution was cooled to −55° C. A solution of difluoromethoxybenzaldehyde (2 g) in dimethoxyethane (5 mL) was added dropwise, and the reaction solution was stirred at the same temperature for two hours. 10 mL of methanol was added to the reaction solution, and the reaction solution was heated under reflux for 15 minutes. The reaction solution was left to cool to room temperature. Then, water and dichloromethane were added and the organic layer was separated. The resulting organic layer was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (elution solvent: heptane-ethyl acetate system) to obtain 1.45 g of the title compound. The property values of the compound are as follows. the reaction solution was stirred at the same temperature for two hours the reaction solution was heated under reflux for 15 minutes The reaction solution was left to cool to room temperature the organic layer was separated The resulting organic layer was dried over anhydrous magnesium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography (elution solvent: heptane-ethyl acetate system)

Conditions: temp:-55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of p-toluenesulfonylmethyl isocyanide (2.4 g) in dimethoxyethane (10 mL) was added to a solution of potassium tert-butoxide (2.68 g) in dimethoxyethane (30 mL) at −35° C., and the reaction solution was stirred at the same temperature for 10 minutes. The reaction solution was cooled to −55° C. A solution of difluoromethoxybenzaldehyde (2 g) in dimethoxyethane (5 mL) was added dropwise, and the reaction solution was stirred at the same temperature for two hours. 10 mL of methanol was added to the reaction solution, and the reaction solution was heated under reflux for 15 minutes. The reaction solution was left to cool to room temperature. Then, water and dichloromethane were added and the organic layer was separated. The resulting organic layer was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (elution solvent: heptane-ethyl acetate system) to obtain 1.45 g of the title compound. The property values of the compound are as follows. the reaction solution was stirred at the same temperature for two hours the reaction solution was heated under reflux for 15 minutes The reaction solution was left to cool to room temperature the organic layer was separated The resulting organic layer was dried over anhydrous magnesium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography (elution solvent: heptane-ethyl acetate system)

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 780 mg of 2-(difluoromethoxy)benzaldehyde and 300 mg of 5-chloro-2-(methylsulfanyl)pyrimidine-4-carboxylic acid 1 in 15 ml of anisole is microwave-heated at 130° C. for 45 min and then again for 15 min and again at 140° C. for 15 min. 160 mg of 5-chloro-2-(methylsulfanyl)pyrimidine-4-carboxylic acid 1 is then added and the mixture is again heated at 130° C. for 30 min. The mixture is concentrated under vacuum and purified on 40 g of silica, elution being carried out with 0-10% of ethyl acetate in heptane, so as to obtain 268 mg of [5-chloro-2-(methylsulfanyl)pyrimidin-4-yl][2-(difluoromethoxy)phenyl]methanol 6 in the form of a colourless oil. again at 140° C. for 15 min the mixture is again heated at 130° C. for 30 min The mixture is concentrated under vacuum purified on 40 g of silica, elution

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 780 mg of 2-(difluoromethoxy)benzaldehyde and 300 mg of 5-chloro-2-(methylsulfanyl)pyrimidine-4-carboxylic acid 1 in 15 ml of anisole is microwave-heated at 130° C. for 45 min and then again for 15 min and again at 140° C. for 15 min. 160 mg of 5-chloro-2-(methylsulfanyl)pyrimidine-4-carboxylic acid 1 is then added and the mixture is again heated at 130° C. for 30 min. The mixture is concentrated under vacuum and purified on 40 g of silica, elution being carried out with 0-10% of ethyl acetate in heptane, so as to obtain 268 mg of [5-chloro-2-(methylsulfanyl)pyrimidin-4-yl][2-(difluoromethoxy)phenyl]methanol 6 in the form of a colourless oil. again at 140° C. for 15 min the mixture is again heated at 130° C. for 30 min The mixture is concentrated under vacuum purified on 40 g of silica, elution