propan-2-yl 3-aminobut-2-enoate

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

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

Procedure: 4.0 g (about 15 mmol) of the compound from Example I are heated to reflux overnight in 100 ml of isopropanol with 2.2 g (15 mmol) of isopropyl 3-amino-2-butenoate. After thin-layer chromatographic checking (SiO2, toluene/ethyl acetate 5:1) shows complete conversion, the reaction mixture is concentrated, the residue is taken up with toluene, the solution is concentrated again and the residue is then purified by filtration on silica gel (eluent: toluene/ethyl acetate 100:1-5:1). A crystallizing yellow oil is obtained, which is recrystallized from methanol at about −15° C. 2.8 g (48%) of the target compound are obtained. the reaction mixture is concentrated the solution is concentrated again the residue is then purified by filtration on silica gel (eluent: toluene/ethyl acetate 100:1-5:1) A crystallizing yellow oil is obtained which is recrystallized from methanol at about −15° C

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

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

Procedure: 4.0 g (about 15 mmol) of the compound from Example I are heated to reflux overnight in 100 ml of isopropanol with 2.2 g (15 mmol) of isopropyl 3-amino-2-butenoate. After thin-layer chromatographic checking (SiO2, toluene/ethyl acetate 5:1) shows complete conversion, the reaction mixture is concentrated, the residue is-taken up with toluene, the solution is concentrated again and the residue is then purified by filtration on silica gel (eluent: toluene/ethyl acetate 100:1-5:1). A crystallizing yellow oil is obtained, which is recrystallized from methanol at about −15° C. 2.8 g (48%) of the target compound are obtained. the reaction mixture is concentrated the residue is-taken up with toluene, the solution is concentrated again the residue is then purified by filtration on silica gel (eluent: toluene/ethyl acetate 100:1-5:1) A crystallizing yellow oil is obtained which is recrystallized from methanol at about −15° C

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

Procedure: 2,3-Dichloro-6-fluorobenzaldehyde (1.44 g, 7.5 mmoles), methyl 4-fluoro-3-oxobutanoate (1.0 g, 7.5 mmoles) and 1-methylethyl 3-amino-2-butenoate (1.06 g, 7.5 mmoles) were heated at 90° under nitrogen with stirring for 2.5 hours. The cooled reaction mixture was chromatographed on silica eluting with ethyl acetate/methylene chloride mixtures. The title compound (1.1 g) was obtained by crystallisation from a petroleum ether (60°-80°)/2-propanol mixture mp 129°-31°. The cooled reaction mixture was chromatographed on silica eluting with ethyl acetate/methylene chloride mixtures

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

Procedure: 2-Fluoro-6-(trifluoromethyl)benzaldehyde (1.51 g, 7.8 mmoles), methyl 4-fluoro-3-oxobutanoate (1.06 g, 7.8 mmoles) and 1-methylethyl 3-amino-2-butenoate (1.13 g, 7.8 mmoles) were heated at 90° under nitrogen with stirring for 2 hours. The cooled reaction mixture was chromatographed twice; first eluting with toluene/ethyl acetate mixtures and then with ethyl acetate/petroleum ether (60°-80°) mixtures. The title compound (0.1 g) was obtained on evaporation of the pure fractions mp 82°-4°. The cooled reaction mixture was chromatographed twice first eluting with toluene/ethyl acetate mixtures with ethyl acetate/petroleum ether (60°-80°)

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

Procedure: 2-Chloro-3-nitrobenzaldehyde (1.38 g, 7.5 mmoles), methyl 4-fluoro-3-oxobutanoate (1.0 g, 7.5 mmoles) and 1-methylethyl 3-amino-2-butenoate (1.06 g, 7.5 mmoles) were heated at 90° for 2.5 hours. The reaction mixture was chromatographed on silica eluting with petroleum ether (60°-80°)/ethyl acetate mixtures. The title compound (1.35 g) was obtained after crystallisation from petroleum ether (60°-80°)/2-propanol. mp 156°-7°. The reaction mixture was chromatographed on silica eluting with petroleum ether (60°-80°)/ethyl acetate mixtures

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

Procedure: 3-Chloro-6-fluoro-2-(trifluoromethyl)benzaldehyde (1.3 g, 5.7 mmoles), methyl 4-fluoro-3-oxobutanoate (0.77 g, 5.7 mmoles) and 1-methylethyl 3-amino-2-butenoate (0.82 g, 5.7 mmoles) were heated under nitrogen with stirring for 1.5 hours at 90°, followed by 1.5 hours at 100° and then 1 hour at 110°. The cooled reaction mixture was chromatographed twice on silica first using methylene chloride as eluent and then toluene/ethyl acetate mixtures. The title compound (0.2 g) was obtained after crystallisation from petroleum ether (60°-80°) mp 142°-3°. followed by 1.5 hours at 100° 1 hour at 110° The cooled reaction mixture was chromatographed twice on silica first using methylene chloride as eluent

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

Procedure: 2-Methyl-3-nitrobenzaldehyde (1.23 g, 7.5 mmoles), methyl 4-fluoro-3-oxobutanoate (1.0 g, 7.5 mmoles) and 1-methylethyl 3-amino-2-butenoate (1.07 g, 7.5 mmoles) were heated with stirring at 80° for 2.5 hours. The cooled residue was chromatographed twice on silica eluting first with ethyl acetate/petroleum ether (60°-80°) and then with ethyl acetate/methylene chloride. The title compound (0.61 g) was obtained by crystallisation from a mixture of petroleum ether (60°-80°) and 2-propanol mp 132°-133°. The cooled residue was chromatographed twice on silica eluting first with ethyl acetate/petroleum ether (60°-80°)

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

Procedure: 2,3-Dichlorobenzaldehyde (1.75 g, 10 mmoles), methyl 4-fluoro-3-oxobutanoate (1.34 g, 10 mmoles) and 1-methylethyl 3-amino-2-butenoate (1.43 g, 10 mmoles) were heated with stirring at 90° for 2.5 hours. The reaction mixture was dissolved in ethyl acetate and chromatographed on silica eluting with petroleum ether (60°-80°)/ethyl acetate mixtures. Pure fractions were combined and evaporated to dryness. The title compound (1.6 g) was obtained by crystallisation from 2-propanol. mp 148°-9°. chromatographed on silica eluting with petroleum ether (60°-80°)/ethyl acetate mixtures evaporated to dryness

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

Procedure: 4.0 g (about 15 mmol) of the compound from Example I are heated to reflux overnight in 100 ml of isopropanol with 2.2 g (15 mmol) of isopropyl 3-amino-2-butenoate. After thin-layer chromatographic checking (SiO2, toluene/ethyl acetate 5:1) shows complete conversion, the reaction mixture is concentrated, the residue is taken up with toluene, the solution is concentrated again and the residue is then purified by filtration on silica gel (eluent: toluene/ethyl acetate 100:1-5:1). A crystallizing yellow oil is obtained, which is recrystallized from methanol at about −15° C. 2.8 g (48%) of the target compound are obtained. the reaction mixture is concentrated the solution is concentrated again the residue is then purified by filtration on silica gel (eluent: toluene/ethyl acetate 100:1-5:1) A crystallizing yellow oil is obtained which is recrystallized from methanol at about −15° C