4-chloro-2-hydroxy-5-methoxybenzaldehyde

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The above prepared 3-chloro-4-methoxy-phenol (2.379 g, 13.5 mmol, corrected for purity) was dissolved in 21 mL of trifluoroacetic acid and treated with hexamethylene tetramine (2.313 g, 1.25 eq.), and the mixture was then stirred at 85° C. over night. Cooling, pouring onto crashed ice, twofold extraction with AcOEt, washing with water, drying over sodium sulfate, and evaporation of the solvents, followed by flash chromatography (SiO2, heptane/AcOiPr=82/18), followed by crystallization from heptane/AcOEt, produced finally 1.030 g of the title compound as yellow crystals. Cooling pouring ice, twofold extraction with AcOEt washing with water drying over sodium sulfate, and evaporation of the solvents followed by crystallization from heptane/AcOEt

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The above prepared 3-chloro-4-methoxy-phenol (2.379 g, 13.5 mmol, corrected for purity) was dissolved in 21 mL of trifluoroacetic acid and treated with hexamethylene tetramine (2.313 g, 1.25 eq.), and the mixture was then stirred at 85° C. over night. Cooling, pouring onto crashed ice, twofold extraction with AcOEt, washing with water, drying over sodium sulfate, and evaporation of the solvents, followed by flash chromatography (SiO2, heptane/AcOiPr=82/18), followed by crystallization from heptane/AcOEt, produced finally 1.030 g of the title compound as yellow crystals. Cooling pouring ice, twofold extraction with AcOEt washing with water drying over sodium sulfate, and evaporation of the solvents followed by crystallization from heptane/AcOEt