diethyl 2-[(4-hydroxyphenyl)methylidene]propanedioate

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 25 mL RB flask fitted with magnetic stirrer was charged with methanol (6 mL) and water (1 mL). To the stirred solvent was added 2-(4-hydroxy-benzylidene)-malonic acid diethyl ester (1 g, 3.8 mmol), followed by potassium cyanide (0.492 g, 7.6 mmol). The RM was heated at 70° C. for 2 h. The RM was concentrated, diluted with saturated NaHCO3 solution (50 mL) and washed with ethyl acetate (50 mL×2). The aqueous layer was acidified to pH 3 with 1N hydrochloric acid and extracted with ethyl acetate (50 mL×2). The organic layer was washed with water (50 mL) and saturated brine solution (50 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as brown liquid. (0.6 g, yield: 72.3%); MS (ESI, 120 eV): m/z=190.0 (M−H)+; 1H NMR (300 MHz, DMSO-d6): δ 12.69 (s, 1H), 9.58 (s, 1H), 7.22-7.24 (d, 2H), 6.75-6.78 (d, 2H), 4.28-4.40 (m, 1H), 2.77-3.12 (m, 2H). To a 25 mL RB flask fitted with magnetic stirrer The RM was concentrated diluted with saturated NaHCO3 solution (50 mL) washed with ethyl acetate (50 mL×2) extracted with ethyl acetate (50 mL×2) The organic layer was washed with water (50 mL) and saturated brine solution (50 mL) The organic layer was dried over anhydrous Na2SO4 the solvent was removed under reduced pressure The product was obtained as brown liquid

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 25 mL RB flask fitted with magnetic stirrer was charged with methanol (6 mL) and water (1 mL). To the stirred solvent was added 2-(4-hydroxy-benzylidene)-malonic acid diethyl ester (1 g, 3.8 mmol), followed by potassium cyanide (0.492 g, 7.6 mmol). The RM was heated at 70° C. for 2 h. The RM was concentrated, diluted with saturated NaHCO3 solution (50 mL) and washed with ethyl acetate (50 mL×2). The aqueous layer was acidified to pH 3 with 1N hydrochloric acid and extracted with ethyl acetate (50 mL×2). The organic layer was washed with water (50 mL) and saturated brine solution (50 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as brown liquid. (0.6 g, yield: 72.3%); MS (ESI, 120 eV): m/z=190.0 (M−H)+; 1H NMR (300 MHz, DMSO-d6): δ 12.69 (s, 1H), 9.58 (s, 1H), 7.22-7.24 (d, 2H), 6.75-6.78 (d, 2H), 4.28-4.40 (m, 1H), 2.77-3.12 (m, 2H). To a 25 mL RB flask fitted with magnetic stirrer The RM was concentrated diluted with saturated NaHCO3 solution (50 mL) washed with ethyl acetate (50 mL×2) extracted with ethyl acetate (50 mL×2) The organic layer was washed with water (50 mL) and saturated brine solution (50 mL) The organic layer was dried over anhydrous Na2SO4 the solvent was removed under reduced pressure The product was obtained as brown liquid

Conditions: temp:125.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 100 mL RB flask fitted with magnetic stirrer was charged with piperidine (0.426 g, 0.5 mL, 5 mmol) and acetic acid (0.3 g, 0.3 mL, 5 mmol). To this, toluene (25 mL) was added, followed by 4-hydroxybenzaldehyde (2 g, 16.4 mmol) and diethyl malonate (3.15 g, 19.7 mmol). The RM was heated at 125° C., by fitted with a dean-stark's apparatus for 5 h. After 5 h, the RM was concentrated; water (50 mL) was added and extracted with ethyl acetate (50 mL×2)). The organic layer was washed with saturated brine solution (50 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as yellow solid. (2 g, yield: 46.2%); MS (ESI, 120 eV): m/z=263.1 (M−H)+; 1H NMR (300 MHz, DMSO-d6): δ 10.27 (s, 1H), 7.58 (s, 1H), 7.36-7.38 (d, 2H), 6.81-6.84 (d, 2H), 4.17-4.32 (m, 4H), 4.06-4.14 (q, 1H), 1.21-1.26 (t, 6H). To a 100 mL RB flask fitted with magnetic stirrer by fitted with a dean-stark's apparatus for 5 h the RM was concentrated water (50 mL) was added extracted with ethyl acetate (50 mL×2)) The organic layer was washed with saturated brine solution (50 mL) The organic layer was dried over anhydrous Na2SO4 the solvent was removed under reduced pressure The product was obtained as yellow solid

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 25 mL RB flask fitted with magnetic stirrer was charged with methanol (6 mL) and water (1 mL). To the stirred solvent was added 2-(4-hydroxy-benzylidene)-malonic acid diethyl ester (1 g, 3.8 mmol), followed by potassium cyanide (0.492 g, 7.6 mmol). The RM was heated at 70° C. for 2 h. The RM was concentrated, diluted with saturated NaHCO3 solution (50 mL) and washed with ethyl acetate (50 mL×2). The aqueous layer was acidified to pH 3 with 1N hydrochloric acid and extracted with ethyl acetate (50 mL×2). The organic layer was washed with water (50 mL) and saturated brine solution (50 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as brown liquid. (0.6 g, yield: 72.3%); MS (ESI, 120 eV): m/z=190.0 (M−H)+; 1H NMR (300 MHz, DMSO-d6): δ 12.69 (s, 1H), 9.58 (s, 1H), 7.22-7.24 (d, 2H), 6.75-6.78 (d, 2H), 4.28-4.40 (m, 1H), 2.77-3.12 (m, 2H). To a 25 mL RB flask fitted with magnetic stirrer The RM was concentrated diluted with saturated NaHCO3 solution (50 mL) washed with ethyl acetate (50 mL×2) extracted with ethyl acetate (50 mL×2) The organic layer was washed with water (50 mL) and saturated brine solution (50 mL) The organic layer was dried over anhydrous Na2SO4 the solvent was removed under reduced pressure The product was obtained as brown liquid

Conditions: temp:125.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 100 mL RB flask fitted with magnetic stirrer was charged with piperidine (0.426 g, 0.5 mL, 5 mmol) and acetic acid (0.3 g, 0.3 mL, 5 mmol). To this, toluene (25 mL) was added, followed by 4-hydroxybenzaldehyde (2 g, 16.4 mmol) and diethyl malonate (3.15 g, 19.7 mmol). The RM was heated at 125° C., by fitted with a dean-stark's apparatus for 5 h. After 5 h, the RM was concentrated; water (50 mL) was added and extracted with ethyl acetate (50 mL×2)). The organic layer was washed with saturated brine solution (50 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as yellow solid. (2 g, yield: 46.2%); MS (ESI, 120 eV): m/z=263.1 (M−H)+; 1H NMR (300 MHz, DMSO-d6): δ 10.27 (s, 1H), 7.58 (s, 1H), 7.36-7.38 (d, 2H), 6.81-6.84 (d, 2H), 4.17-4.32 (m, 4H), 4.06-4.14 (q, 1H), 1.21-1.26 (t, 6H). To a 100 mL RB flask fitted with magnetic stirrer by fitted with a dean-stark's apparatus for 5 h the RM was concentrated water (50 mL) was added extracted with ethyl acetate (50 mL×2)) The organic layer was washed with saturated brine solution (50 mL) The organic layer was dried over anhydrous Na2SO4 the solvent was removed under reduced pressure The product was obtained as yellow solid