ethyl 5-benzyl-1H-pyrrole-2-carboxylate

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of Ethyl 5-benzylpyrrole-2-carboxylate (0.7 g, 3.05 mmol; Elder et al., Synthetic Communications, 19, 763-767 (1989)), ethanol (20 ml) and 1M sodium hydroxide (9.2 ml, 9.2 mmol) was stirred and heated under reflux for 3 h. The major part of the ethanol was removed and the remaining liquid was diluted with water, washed with ether, cooled in ice and acidified with concentrated hydrochloric acid. The mixture was extracted with ether. The combined extracts were washed with brine, dried (Na2SO4) and concentrated to afford 0.567 g (92%) of an off white solid: mp. 130°-134° C.; 1H NMR(CDCl3) δ 8.87 (1H, brs), 7.37-6.95 (5H, m), 6.97 (1H, m), 6.07 (1H, m), 4.00 (2H, s). heated under reflux for 3 h The major part of the ethanol was removed the remaining liquid was diluted with water washed with ether cooled in ice The mixture was extracted with ether The combined extracts were washed with brine dried (Na2SO4) concentrated to afford 0.567 g (92%) of an off white solid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of Ethyl 5-benzylpyrrole-2-carboxylate (0.7 g, 3.05 mmol; Elder et al., Synthetic Communications, 19, 763-767 (1989)), ethanol (20 ml) and 1M sodium hydroxide (9.2 ml, 9.2 mmol) was stirred and heated under reflux for 3 h. The major part of the ethanol was removed and the remaining liquid was diluted with water, washed with ether, cooled in ice and acidified with concentrated hydrochloric acid. The mixture was extracted with ether. The combined extracts were washed with brine, dried (Na2SO4) and concentrated to afford 0.567 g (92%) of an off white solid: mp. 130°-134° C.; 1H NMR(CDCl3) δ 8.87 (1H, brs), 7.37-6.95 (5H, m), 6.97 (1H, m), 6.07 (1H, m), 4.00 (2H, s). heated under reflux for 3 h The major part of the ethanol was removed the remaining liquid was diluted with water washed with ether cooled in ice The mixture was extracted with ether The combined extracts were washed with brine dried (Na2SO4) concentrated to afford 0.567 g (92%) of an off white solid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of Ethyl 5-benzylpyrrole-2-carboxylate (0.7 g, 3.05 mmol; Elder et al., Synthetic Communications, 19, 763-767 (1989)), ethanol (20 ml) and 1M sodium hydroxide (9.2 ml, 9.2 mmol) was stirred and heated under reflux for 3 h. The major part of the ethanol was removed and the remaining liquid was diluted with water, washed with ether, cooled in ice and acidified with concentrated hydrochloric acid. The mixture was extracted with ether. The combined extracts were washed with brine, dried (Na2SO4) and concentrated to afford 0.567 g (92%) of an off white solid: mp. 130-134° C.; 1H NMR (CDCl3) δ 8.87 (1H, brs), 7.37-6.95 (5H, m), 6.97 (1H, m), 6.07 (1H, m), 4.00 (2H, s). heated under reflux for 3 h The major part of the ethanol was removed the remaining liquid was diluted with water washed with ether cooled in ice The mixture was extracted with ether The combined extracts were washed with brine dried (Na2SO4) concentrated to afford 0.567 g (92%) of an off white solid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of Ethyl 5-benzylpyrrole-2-carboxylate (0.7 g, 3.05 mmol; Elder et al., Synthetic Communications, 19, 763-767 (1989)), ethanol (20 ml) and 1M sodium hydroxide (9.2 ml, 9.2 mmol) was stirred and heated under reflux for 3 h. The major part of the ethanol was removed and the remaining liquid was diluted with water, washed with ether, cooled in ice and acidified with concentrated hydrochloric acid. The mixture was extracted with ether. The combined extracts were washed with brine, dried (Na2SO4) and concentrated to afford 0.567 g (92%) of an off white solid: mp. 130-134° C.; 1H NMR (CDCl3) δ 8.87 (1H, brs), 7.37-6.95 (5H, m), 6.97 (1H, m), 6.07 (1H, m), 4.00 (2H, s). heated under reflux for 3 h The major part of the ethanol was removed the remaining liquid was diluted with water washed with ether cooled in ice The mixture was extracted with ether The combined extracts were washed with brine dried (Na2SO4) concentrated to afford 0.567 g (92%) of an off white solid

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of Ethyl 5-benzylpyrrole-2-carboxylate (0.7 g, 3.05 mmol; Elder et al., Synthetic Communications, 19, 763-767 (1989)), ethanol (20 ml) and 1M sodium hydroxide (9.2 ml, 9.2 mmol) was stirred and heated under reflux for 3 h. The major part of the ethanol was removed and the remaining liquid was diluted with water, washed with ether, cooled in ice and acidified with concentrated hydrochloric acid. The mixture was extracted with ether. The combined extracts were washed with brine, dried (Na2SO4) and concentrated to afford 0.567 g (92%) of an off white solid: mp. 130°-134° C.; 1H NMR (CDCl3) δ 8.87 (1H, brs), 7.37-6.95 (5H, m), 6.97 (1H, m), 6.07 (1H, m), 4.00 (2H, s). heated under reflux for 3 h The major part of the ethanol was removed the remaining liquid was diluted with water washed with ether cooled in ice The mixture was extracted with ether The combined extracts were washed with brine dried (Na2SO4) concentrated to afford 0.567 g (92%) of an off white solid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of Ethyl 5-benzylpyrrole-2-carboxylate (0.7 g, 3.05 mmol; Elder et al., Synthetic Communications, 19, 763-767 (1989)), ethanol (20 ml) and 1M sodium hydroxide (9.2 ml, 9.2 mmol) was stirred and heated under reflux for 3 h. The major part of the ethanol was removed and the remaining liquid was diluted with water, washed with ether, cooled in ice and acidified with concentrated hydrochloric acid. The mixture was extracted with ether. The combined extracts were washed with brine, dried (Na2SO4) and concentrated to afford 0.567 g (92%) of an off white solid: mp. 130-134° C.; 1H NMR(CDCl3) δ8.87 (1H, brs), 7.37-6.95 (5H, m), 6.97 (1H, m), 6.07 (1H, m), 4.00 (2H, s). heated under reflux for 3 h The major part of the ethanol was removed the remaining liquid was diluted with water washed with ether cooled in ice The mixture was extracted with ether The combined extracts were washed with brine dried (Na2SO4) concentrated to afford 0.567 g (92%) of an off white solid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of Ethyl 5-benzylpyrrole-2-carboxylate (0.7 g, 3.05 mmol; Elder et al., Synthetic Communications, 19, 763-767 (1989)), ethanol (20 ml) and 1M sodium hydroxide (9.2 ml, 9.2 mmol) was stirred and heated under reflux for 3 h. The major part of the ethanol was removed and the remaining liquid was diluted with water, washed with ether, cooled in ice and acidified with concentrated hydrochloric acid. The mixture was extracted with ether. The combined extracts were washed with brine, dried (Na2SO4) and concentrated to afford 0.567 g (92%) of an off white solid: mp. 130-134° C.; 1H NMR(CDCl3) δ 8.87 (1H, brs), 7.37-6.95 (5H, m), 6.97 (1H, m), 6.07 (1H, m), 4.00 (2H, s). heated under reflux for 3 h The major part of the ethanol was removed the remaining liquid was diluted with water washed with ether cooled in ice The mixture was extracted with ether The combined extracts were washed with brine dried (Na2SO4) concentrated to afford 0.567 g (92%) of an off white solid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Freshly prepared aq. NaOH (10 M in H2O, 4.78 mmol) was added to a stirring, room temperature solution of 31 (0.2190 g, 0.955 mmol) in MeOH (2.4 mL, 0.4 M) under N2. The reaction was heated to reflux until the reaction was judged complete by HPLC (40 min). The product was concentrated and then dissolved in 1.9 mL H2O. 10% aq. HCl was added dropwise until the pH=2. The white solid that precipitated from the reaction was filtered off and washed with cold H2O. The solid was dried under vacuum overnight to obtain 32 as a pale pink, impure solid (0.0845 g). 32 was further purified by adding CHCl3, stirring, and filtering off pure white 32 (0.0445 g). Note. The undesired impurity has a retention time of 9.643 min by HPLC. Also, the 13C NMR of 32 at room temperature showed doublets for the peaks corresponding to the pyrrole carbons, benzyl carbon, and acid carbon. When the NMR probe was heated to 28° C., all doubled peaks collapsed into single peaks as reported below. 1H (CD3OD, 400 MHz): δ 11.04 (1H, broad s), 7.27-7.13 (5H, m), 6.80 (1H, d, J=3.4 Hz), 5.87 (1H, d, J=3.4 Hz) 3.93 (2H, s) ppm. 13C (CD3OD, 100 MHz): δ 164.52, 140.71, 139.04, 129.56, 129.42, 127.27, 122.77, 117.59, 109.66, 34.65 ppm. DEPT (CD3OD, 100 MHz): CH2 carbons: 34.65; CH carbons: 129.56, 129.42, 127.27, 117.59, 109.66 ppm. HPLC: 8.698 min. The reaction was heated to reflux until the reaction was judged complete by HPLC (40 min) The product was concentrated dissolved in 1.9 mL H2O 10% aq. HCl was added dropwise until the pH=2 The white solid that precipitated from the reaction was filtered off washed with cold H2O The solid was dried under vacuum overnight