benzyl propanoate

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

Procedure: To a solution of (S)-2-amino-3-(3′-chloro-biphenyl-4-yl)-propionic acid benzyl ester (10.0 g, 24.9 mmol) in dichloromethane (100 mL) was added triethylamine (10.4 mL, 74.6 mmol) at 0° C. After stirred for 10 min, ethyl (R)-2-(trifluoromethylsulfonyloxy)propionate (9.3 mL, 49.5 mmol) was added at room temperature and stirred for 1 hour. Additional triethylamine (10.4 mL, 74.6 mmol) and ethyl (R)-2-(trifluoromethylsulfonyloxy)propionate (9.3 mL, 49.5 mmol) were added at room temperature and stirred for additional 2 hours. The reaction mixture was washed with H2O and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (EtOAc/heptane) to give (S)-3-(3′-chloro-biphenyl-4-yl)-2-(S)-1-ethoxycarbonyl-ethylamino)-propionic acid benzyl ester. 1H NMR (400 MHz, CDCl3) δ 1.21 (t, 3H, J=7.3 Hz), 1.27 (d, 3H, J=6.8 Hz), 1.89 (bs, 1H), 2.95-3.07 (m, 2H), 3.38 (dd, 1H, J=6.8, 14.8 Hz), 3.69 (dd, 1H, J=7.1, 7.1 Hz), 4.06-4.17 (m, 2H), 5.06 (d, 1H, J=12.1 Hz), 5.12 (d, 1H, J=12.1 Hz), 7.20-7.25 (m, 4H), 7.28-7.34 (m, 4H), 7.35 (dd, 1H, J=7.6, 7.6 Hz), 7.41-7.46 (m, 3H), 7.53 (dd, 1H, J=1.5, 1.5 Hz); MS: m/z (MH+) 466. stirred for 1 hour stirred for additional 2 hours The reaction mixture was washed with H2O the organic layer was concentrated under reduced pressure The obtained residue was purified by silica gel column chromatography (EtOAc/heptane)

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

Procedure: To a solution of (S)-2-amino-3-(3′-chloro-biphenyl-4-yl)-propionic acid benzyl ester (10.0 g, 24.9 mmol) in dichloromethane (100 mL) was added triethylamine (10.4 mL, 74.6 mmol) at 0° C. After stirred for 10 min, ethyl (R)-2-(trifluoromethylsulfonyloxy)propionate (9.3 mL, 49.5 mmol) was added at room temperature and stirred for 1 hour. Additional triethylamine (10.4 mL, 74.6 mmol) and ethyl (R)-2-(trifluoromethylsulfonyloxy)propionate (9.3 mL, 49.5 mmol) were added at room temperature and stirred for additional 2 hours. The reaction mixture was washed with H2O and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (EtOAc/heptane) to give (S)-3-(3′-chloro-biphenyl-4-yl)-2-(S)-1-ethoxycarbonyl-ethylamino)-propionic acid benzyl ester. 1H NMR (400 MHz, CDCl3) δ 1.21 (t, 3H, J=7.3 Hz), 1.27 (d, 3H, J=6.8 Hz), 1.89 (bs, 1H), 2.95-3.07 (m, 2H), 3.38 (dd, 1H, J=6.8, 14.8 Hz), 3.69 (dd, 1H, J=7.1, 7.1 Hz), 4.06-4.17 (m, 2H), 5.06 (d, 1H, J=12.1 Hz), 5.12 (d, 1H, J=12.1 Hz), 7.20-7.25 (m, 4H), 7.28-7.34 (m, 4H), 7.35 (dd, 1H, J=7.6, 7.6 Hz), 7.41-7.46 (m, 3H), 7.53 (dd, 1H, J=1.5, 1.5 Hz); MS: m/z (MH+) 466. stirred for 1 hour stirred for additional 2 hours The reaction mixture was washed with H2O the organic layer was concentrated under reduced pressure The obtained residue was purified by silica gel column chromatography (EtOAc/heptane)

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

Procedure: A suspension of 3.72 g (0.032 mol) of rac.-2-amino-3-(3-hydroxyphenyl)propanoic acid benzyl ester in 400 mL of ice cold dichloromethane was treated dropwise with 1.9 mL (0.020 mol) of acetic anhydride. Upon completion of the addition, a solution of 3.70 g of sodium carbonate in 30 mL of water was added simultaneously with an additional 1.9 mL of acetic anhydride. After 1 hour, the layers were separated and the organic layer was washed with water. The combined aqueous layers were extracted with dichloromethane and the combined is extracts were washed with brine and dried over magnesium sulfate. Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges, eluting with 20% ethyl acetate-hexane to give 8.49 g (84%) of rac.-2-acetamido-3-hydroxyphenyl)propanoic acid benzyl ester as a thick oil. Upon completion of the addition the layers were separated the organic layer was washed with water The combined aqueous layers were extracted with dichloromethane were washed with brine dried over magnesium sulfate Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges eluting with 20% ethyl acetate-hexane

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To anhydrous tetrahydrofuran (5 mL) was added diisopropylamine (759 mg, 7.5 mmol) under nitrogen stream, and the mixture was cooled to −78° C. To the solution was added a 1.58 M n-butyl lithium-hexane solution (4.3 mL, 6.8 mmol), and the mixture was stirred at −78° C. for 5 min, and then at 0° C. for 15 min. The solution of lithium diisopropylamide tetrahydrofuran was cooled to −78° C., and a solution of benzyl propionate (821 mg, 5.0 mmol) in anhydrous tetrahydrofuran (10 mL) was added dropwise over 1 h, and the reaction mixture was further stirred at −78° C. for 1 h. The enolate thus prepared was added via a cannula to a solution of benzyl 3-methyl-2-ketobutyrate (1.24 g, 6.0 mmol) in anhydrous tetrahydrofuran (5 mL) having been cooled to −78° C. After stirring at −78° C. for 2 h, the reaction mixture was diluted with a 10% aqueous citric acid solution, and extracted with ethyl acetate. The organic layer was washed with 1 M hydrochloric acid, saturated aqueous sodium hydrogen carbonate and brine, dried over anhydrous magnesium sulfate, and filtered. The solvent was evaporated under reduced pressure, and the residue thus obtained was subjected to silica gel column chromatography (hexane-ethyl acetate 9:1) to give 1.22 g of dibenzyl 2-isopropyl-2-hydroxy-3-methylsuccinate as oil (yield: 66%) in the form of a diastereomer mixture. To the solution was added a 1.58 M n-butyl lithium-hexane solution (4.3 mL, 6.8 mmol) at 0° C. for 15 min the reaction mixture was further stirred at −78° C. for 1 h having been cooled to −78° C After stirring at −78° C. for 2 h extracted with ethyl acetate The organic layer was washed with 1 M hydrochloric acid, saturated aqueous sodium hydrogen carbonate and brine dried over anhydrous magnesium sulfate filtered The solvent was evaporated under reduced pressure the residue thus obtained

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

Procedure: A suspension of 8.72 g (0.032 mol) of rac.-2-amino-3-(3-hydroxyphenyl)propanoic acid benzyl ester in 400 mL of ice cold dichloromethane was treated dropwise with 1.9 mL (0.020 mol) of acetic anhydride. Upon completion of the addition, a solution of 3.70 g of sodium carbonate in 30 mL of water was added simultaneously with an additional 1.9 mL of acetic anhydride. After 1 hour, the layers were separated and the organic layer was washed with water. The combined aqueous layers were extracted with dichloromethane and the combined extracts were washed with brine and dried over magnesium sulfate. Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges, eluting with 20% ethyl acetate-hexane to give 8.49 g (84%) of rac.-2-acetamido-3-hydroxyphenyl)propanoic acid benzyl ester as a thick oil. Upon completion of the addition the layers were separated the organic layer was washed with water The combined aqueous layers were extracted with dichloromethane the combined extracts were washed with brine dried over magnesium sulfate Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges eluting with 20% ethyl acetate-hexane

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

Procedure: A suspension of 8.72 g (0.032 mol) of rac.-2-amino-3-(3-hydroxyphenyl)propanoic acid benzyl ester in 400 mL of ice cold dichloromethane was treated dropwise with 1.9 mL (0.020 mol) of acetic anhydride. Upon completion of the addition, a solution of 3.70 g of sodium carbonate in 30 mL of water was added simultaneously with an additional 1.9 mL of acetic anhydride. After 1 hour, the layers were separated and the organic layer was washed with water. The combined aqueous layers were extracted with dichloromethane and the combined extracts were washed with brine and dried over magnesium sulfate. Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges, eluting with 20% ethyl acetate-hexane to give 8.49 g (84%) of rac.-2-acetamido-3-hydroxyphenyl)propanoic acid benzyl ester as a thick oil. Upon completion of the addition the layers were separated the organic layer was washed with water The combined aqueous layers were extracted with dichloromethane the combined extracts were washed with brine dried over magnesium sulfate Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges eluting with 20% ethyl acetate-hexane

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

Procedure: The title compound was prepared using the protocol described in steps A and B for the preparation of 1-isocyanato-indolizine-3-carboxylic acid benzyl ester scheme A6 using bromo-acetic acid allyl ester in step A and propionic acid benzyl ester in step B. TLC, Rf (c-hexane/EtOAc 1:1)=0.8; MS (LC/MS): 336.1 [M+H]+, 358.1 [M+Na]+, 693.2 [2M+Na]+; tR (HPLC conditions a): 4.55 min. 4.55 min.

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

Procedure: The activated esters of type (3) react with alcohols, and also with phenols, thiophenols or mercaptans, to form esters. For example, activated propionic acid and benzyl alcohol in tetrahydrofuran, in the presence of triethylamine, give a very good yield of benzyl propionate.

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

Procedure: To a solution of (S)-2-amino-3-(3′-chloro-biphenyl-4-yl)-propionic acid benzyl ester (10.0 g, 24.9 mmol) in dichloromethane (100 mL) was added triethylamine (10.4 mL, 74.6 mmol) at 0° C. After stirred for 10 min, ethyl (R)-2-(trifluoromethylsulfonyloxy)propionate (9.3 mL, 49.5 mmol) was added at room temperature and stirred for 1 hour. Additional triethylamine (10.4 mL, 74.6 mmol) and ethyl (R)-2-(trifluoromethylsulfonyloxy)propionate (9.3 mL, 49.5 mmol) were added at room temperature and stirred for additional 2 hours. The reaction mixture was washed with H2O and the organic layer was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (EtOAc/heptane) to give (S)-3-(3′-chloro-biphenyl-4-yl)-2-(S)-1-ethoxycarbonyl-ethylamino)-propionic acid benzyl ester. 1H NMR (400 MHz, CDCl3) δ 1.21 (t, 3H, J=7.3 Hz), 1.27 (d, 3H, J=6.8 Hz), 1.89 (bs, 1H), 2.95-3.07 (m, 2H), 3.38 (dd, 1H, J=6.8, 14.8 Hz), 3.69 (dd, 1H, J=7.1, 7.1 Hz), 4.06-4.17 (m, 2H), 5.06 (d, 1H, J=12.1 Hz), 5.12 (d, 1H, J=12.1 Hz), 7.20-7.25 (m, 4H), 7.28-7.34 (m, 4H), 7.35 (dd, 1H, J=7.6, 7.6 Hz), 7.41-7.46 (m, 3H), 7.53 (dd, 1H, J=1.5, 1.5 Hz); MS: m/z (MH+) 466. stirred for 1 hour stirred for additional 2 hours The reaction mixture was washed with H2O the organic layer was concentrated under reduced pressure The obtained residue was purified by silica gel column chromatography (EtOAc/heptane)

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

Procedure: A suspension of 3.72 g (0.032 mol) of rac.-2-amino-3-(3-hydroxyphenyl)propanoic acid benzyl ester in 400 mL of ice cold dichloromethane was treated dropwise with 1.9 mL (0.020 mol) of acetic anhydride. Upon completion of the addition, a solution of 3.70 g of sodium carbonate in 30 mL of water was added simultaneously with an additional 1.9 mL of acetic anhydride. After 1 hour, the layers were separated and the organic layer was washed with water. The combined aqueous layers were extracted with dichloromethane and the combined is extracts were washed with brine and dried over magnesium sulfate. Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges, eluting with 20% ethyl acetate-hexane to give 8.49 g (84%) of rac.-2-acetamido-3-hydroxyphenyl)propanoic acid benzyl ester as a thick oil. Upon completion of the addition the layers were separated the organic layer was washed with water The combined aqueous layers were extracted with dichloromethane were washed with brine dried over magnesium sulfate Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges eluting with 20% ethyl acetate-hexane