1,2-difluoro-3-prop-2-ynoxybenzene

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

Procedure: A mixture of 7,8-difluoro-2H-chromene and 1,2-difluoro-3-prop-2-ynyloxybenzene (43.2 g) is hydrogenated at 20° C. for 1 h in 430 ml of THF in the presence of Pd/C (5% Pd). The batch is concentrated to dryness, and the crude product is purified by column chromatography (SiO2, n-pentane:1-chlorobutane=4:1), giving pure 7,8-difluorochroman as a slightly yellowish liquid. The batch is concentrated to dryness the crude product is purified by column chromatography (SiO2, n-pentane:1-chlorobutane=4:1)

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

Procedure: A mixture of 7,8-difluoro-2H-chromene and 1,2-difluoro-3-prop-2-ynyloxybenzene (43.2 g) is hydrogenated at 20° C. for 1 h in 430 ml of THF in the presence of Pd/C (5% Pd). The batch is concentrated to dryness, and the crude product is purified by column chromatography (SiO2, n-pentane:1-chlorobutane=4:1), giving pure 7,8-difluorochroman as a slightly yellowish liquid. The batch is concentrated to dryness the crude product is purified by column chromatography (SiO2, n-pentane:1-chlorobutane=4:1)

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

Procedure: 115.0 g (0.88 mol) of 2,3-difluorophenol are refluxed for 3 h together with 118.2 ml (17.7 mol) of propargyl bromide (80% soln. in toluene) and 146.6 g (138.2 mol) of potassium carbonate in 1.6 l of ethyl methyl ketone. The batch is filtered, and the filter residue is washed with MTBE. The filtrate is concentrated to dryness, and the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1). The batch is filtered the filter residue is washed with MTBE The filtrate is concentrated to dryness the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1)

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

Procedure: 115.0 g (0.88 mol) of 2,3-difluorophenol are refluxed for 3 h together with 118.2 ml (17.7 mol) of propargyl bromide (80% soln. in toluene) and 146.6 g (138.2 mol) of potassium carbonate in 1.6 l of ethyl methyl ketone. The batch is filtered, and the filter residue is washed with MTBE. The filtrate is concentrated to dryness, and the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1). The batch is filtered the filter residue is washed with MTBE The filtrate is concentrated to dryness the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1)

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

Procedure: 115.0 g (0.88 mol) of 2,3-difluorophenol are refluxed for 3 h together with 118.2 ml (17.7 mol) of propargyl bromide (80% soln. in toluene) and 146.6 g (138.2 mol) of potassium carbonate in 1.6 l of ethyl methyl ketone. The batch is filtered, and the filter residue is washed with MTBE. The filtrate is concentrated to dryness, and the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1). The batch is filtered the filter residue is washed with MTBE The filtrate is concentrated to dryness the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1)

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

Procedure: A mixture of 7,8-difluoro-2H-chromene and 1,2-difluoro-3-prop-2-ynyloxybenzene (43.2 g) is hydrogenated at RT for 1 h in 430 ml of THF in the presence of Pd/C (5% of Pd). The batch is evaporated to dryness, and the crude product is purified by column chromatography (SiO2, n-pentane: 1-chlorobutane=4:1), giving pure 7,8-difluorochroman as a pale-yellowish liquid. The batch is evaporated to dryness the crude product is purified by column chromatography (SiO2, n-pentane: 1-chlorobutane=4:1)

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

Procedure: 115.0 g (0.88 mol) of 2,3-difluorophenol are refluxed for 3 h in 1.6 l of ethyl methyl ketone together with 118.2 ml (17.7 mol) of propargyl bromide (80% soln. in toluene) and 146.6 g (138.2 mol) of potassium carbonate. The batch is filtered, and the filter residue is washed with MTBE. The filtrate is evaporated to dryness, and the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1). The batch is filtered the filter residue is washed with MTBE The filtrate is evaporated to dryness the residue is purified by column chromatography (SiO2, n-heptane:MTBE=3:1)