2,2,2-trifluoro-1-(3,4,5-trichlorophenyl)ethanone

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: LiH (0.41 g) is added to a solution of 2,2,2-trifluoro-1-(3,4,5-trichloro-phenyl)-ethanone (6.76 g) and 5-acetyl-3-methyl-furan-2-carboxylic acid methyl ester (4.46 g) in THF (50 ml). After 3 hours at 60° C. methyl tert-butyl ether (MTBE, 20 ml) is added and the reaction mixture is poured into water (20 ml) at 0° C. The organic phase is extracted once with water and a saturated aqueous solution of NaCl, dried over MgSO4 and concentrated in vacuo to yield 11.9 g of 3-methyl-5-[4,4,4-trifluoro-3-hydroxy-3-(3,4,5-trichloro-phenyl)-butyryl]-furan-2-carboxylic acid methyl ester. The crude product is used without further purification. MS (HPLC/MS): 459 (MH+). Retention time: 2.01 min. The organic phase is extracted once with water a saturated aqueous solution of NaCl, dried over MgSO4 concentrated in vacuo

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

Procedure: LiH (1.76 g) is added to a solution of 2,2,2-trifluoro-1-(3,4,5-trichloro-phenyl)-ethanone (35.33 g) and 5-acetyl-2-methyl-furan-3-carboxylic acid methyl ester (20 g) in THF (300 ml). After 1 hour 30 at 60° C. MTBE is added (450 ml) and the reaction mixture is poured onto water (750 ml) at 0° C. The organic phase is washed with water and a saturated aqueous solution of NaCl dried over MgSO4 and concentrated in vacuo to yield 62.3 g of 2-methyl-5-[4,4,4-trifluoro-3-hydroxy-3-(3,4,5-trichloro-phenyl)-butyryl]-furan-3-carboxylic acid methyl ester. The crude product is used without further purification. MS (HPLC/MS): 459 (MH+). the reaction mixture is poured onto water (750 ml) at 0° C The organic phase is washed with water a saturated aqueous solution of NaCl dried over MgSO4 concentrated in vacuo

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

Procedure: n-BuLi (16.5 ml, 2.5M in hexane) is added over 20 minutes to a solution of 5-bromo-1,2,6-trichloro-benzene (10.2 g) in diethyl ether (150 ml) under nitrogen at −78° C. After 20 minutes at −78° C., a solution of ethyl trifluoroacetate (5.15 ml) in diethyl ether (50 ml) is added over 15 minutes to the reaction mixture. After 40 minutes at −78° C., the reaction mixture is slowly warmed up to room temperature and then quenched with a saturated aqueous solution of NH4Cl. The aqueous phase is extracted three times with diethyl ether. The combined organic phases are dried over Na2SO4 and concentrated in vacuo. The crude product is purified by vacuum distillation to yield 2,2,2-trifluoro-1-(3,4,5-trichloro-phenyl)-ethanone (9.20 g) as a yellow solid. After 40 minutes at −78° C. quenched with a saturated aqueous solution of NH4Cl The aqueous phase is extracted three times with diethyl ether The combined organic phases are dried over Na2SO4 concentrated in vacuo The crude product is purified by vacuum distillation

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

Procedure: In 100 mL two neck RBF equipped with dean-stark apparatus a stirred solution of tert-butyl 5′-acetyl-3′H-spiro[azetidine-3,1′-isobenzofuran]-1-carboxylate (Preparation 1, 4.5 g, 14.851 mmol) in toluene (13.5 mL) and trifluorotoluene (13.5 mL) was added 2,2,2-trifluoro-1-(3,4,5-trichlorophenyl)-ethanone (4.44 g, 17.079 mmol) and Cs2CO3 (0.483 g, 1.485 mmol) at room temperature. Resulting reaction mixture was heated at 110° C. for 16 hours. After complete consumption of starting material, reaction mixture was diluted with ter-butylmethyl ether (30 mL) and filtered through celite bed. Filtrate was concentrated under vacuum to afford brown sticky oil (9.01 g, crude). Crude compound was purified by column chromatography using silica gel (230-400 mesh). Desired compound was eluted in 20% ethyl acetate in n-hexane to give light yellow solid (6.54 g, 80.64%). 1H NMR (400 MHz, CDCl3) δ: 1.47 (s, 9H), 4.10 (d, J=9.52 Hz, 2H), 4.32 (d, J=9.36 Hz, 2H), 5.12 (s, 2H), 7.20 (d, J=9.76 Hz, 2H), 7.39 (s, 1H), 7.56 (d, J=7.96 Hz, 1H), 7.67 (s, 1H), 7.84 (d, J=7.96 Hz, 1H). LC-MS (m/z): 374.1 (M+H). Resulting reaction mixture After complete consumption of starting material, reaction mixture was diluted with ter-butylmethyl ether (30 mL) filtered through celite bed Filtrate was concentrated under vacuum to afford brown sticky oil (9.01 g, crude) Crude compound was purified by column chromatography Desired compound was eluted in 20% ethyl acetate in n-hexane

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

Procedure: In 100 mL two neck RBF fitted with dean-stark apparatus, a stirred solution of tert-butyl 5′-acetyl-3′H-spiro[azetidine-3,1′-isobenzofuran]-1-carboxylate (Preparation 1, 7 g, 23.1mmol) in toluene (21 mL) and trifluoro methyl benzene (21 mL) was added followed by addition of 2,2,2-trifluoro-1-(3,4,5-trichlorophenyl)ethanone (7.37 g, 26.6 mmol) and Cs2CO3 (0.751 g, 2.31 mmol) at room temperature. Resulting reaction mixture was stirred at 110° C. for 16 hours. Reaction was monitored by TLC, after complete consumption of starting material; reaction mixture was dissolved in tert-butyl methyl ether (50 mL), and filtered through celite bed. The filtrate was concentrated under reduced pressure to get crude compound as brown sticky oil 14.1 g. Purification was done by column chromatography using silica gel 230-400 mesh. Desired compound was eluted in 20% ethyl acetate in n-hexane to give compound as light yellow solid (8.6 g, 66.15%). 1H NMR (400 MHz, CDCl3) δ: 1.47 (s, 9H), 4.11 (d, J=9.6 Hz, 2H), 4.32 (d, J=9.52 Hz, 2H), 5.12 (s, 2H), 7.28 (s, 1H), 7.40 (m, 1H), 7.54-7.56 (m, 1H), 7.66 (s, 1H), 7.83 (d, J=7.92 Hz, 1H). VETERINARY (m/z): 560.0 (M−H). Resulting reaction mixture Reaction after complete consumption of starting material reaction mixture filtered through celite bed The filtrate was concentrated under reduced pressure to get crude compound as brown sticky oil 14.1 g Purification Desired compound was eluted in 20% ethyl acetate in n-hexane