2-chloro-5-hydroxy-4-methoxybenzaldehyde

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

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

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

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

Procedure: A mixture of crude 2-chloro-5-hydroxy-4-methoxy-benzaldehyde (1.79 g, 8.15 mmol), 1-bromo-3-methoxypropane (1.53 g, 9.79 mmol) and anhydrous K2CO3 (1.69 g, 12.2 mmol) in MeCN (30 mL) is refluxed overnight. Ice water is added to the mixture, followed by extraction with AcOEt. The combined organics are washed with brine, dried (Na2SO4) and concentrated. The title compound is obtained after purification by RP-HPLC on a PrepC18 OBD column (dimensions: 30×100 mm; 5 μM particle size, SunFire Ltd), and using a 95-5% gradient of MeCN/H2O 5:95 (containing 0.1% TFA) to MeCN/H2O 95:5 (containing 0.1% TFA) over 20 min, as white solid. TLC, Rf (hexane/AcOEt 1:1)=0.42. MS: 259.0 [M+H]+. ]+. tR (HPLC, Nucleosil C18HD column, 20-100% CH3CN/H2O/6 min, 100% CH3CN/2 min, CH3CN and H2O containing 0.1% TFA, flow: 1 mL/min): 4.15 min. 1H-NMR (CDCl3): δ 2.15 (m, 2H), 3.39 (s, 3H), 3.59 (m, 2H), 3.99 (s, 3H), 4.19 (m, 2H), 6.91 (s, 1H), 7.45 (s, 1H), 10.4 (s, 1H) ppm. is refluxed overnight followed by extraction with AcOEt The combined organics are washed with brine dried (Na2SO4) concentrated

Conditions: temp:65.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Chloro-4,5-dimethoxybenzaldehyde (5.00 g, 24.9 mmol; commercially available from Akos Consulting) is dissolved at room temperature in conc. H2SO4 (23 mL; Riedel) at room temperature. The deeply colored mixture is heated at 65° C. overnight with stirring, and after cooling is poured with caution into ice-water containing 38 g of solid NaOH (pH 14). The water phase is washed twice with AcOEt, and then is adjusted to pH 1 by addition of HCl 37% with ice-cooling to form a white suspension. Extraction with AcOEt, drying of the organics over MgSO4 and evaporation gives the crude product in a mixture with unreacted starting material. The title compound is obtained after silica gel chromatography (hexane/AcOEt gradient from 3:1 to 1:1) as white solid. TLC, Rf (hexane/AcOEt 1:1)=0.35. MS: 187.0 [M+H]+. ]+. 1H-NMR (DMSO-d6): δ 3.41 (s, 3H), 7.14 (s, 1H), 7.45 (s, 1H), 9.83 (s, 1H), 10.2 (s, 1H) ppm. after cooling The water phase is washed twice with AcOEt is adjusted to pH 1 by addition of HCl 37% with ice- cooling to form a white suspension Extraction with AcOEt drying of the organics over MgSO4 and evaporation gives the crude product in a mixture