taken from a vespiary thread (which references patent US3867458), check the link (or patent) if ur having issues since a discussion starts after the original post >_< u can use the product 2 make drugs in the 2c- series
Abstract - A process for preparing 2-alkoxy-5-methoxybenzaldehyde, said alkoxy group being a methoxy or an ethoxy group, which comprises reacting, in the presence of potassium carbonate, 2-hydroxy-5-methoxybenzaldehyde with a dialkyl sulfate, said alkyl group being a methyl or an ethyl group, is enclosed.
Example 1 - 50 g of 2-hydroxy-5-methoxybenzaldehyde, 68 g of potassium carbonate and 50 g of dimethyl sulfate were refluxed in 250 mL of acetone for about 3 hours under stirring. After the reaction, the reaction mixture was filtered and the acetone was distilled off from the filtrate and then the residue was poured into 300 mL of water. The precipitated crystals were collected by filtration and dried whereby 45 g of 2,5-dimethoxybenzaldehyde having a melting point of 48°C were obtained (Yield: 82.5%).
Example 2 - On standing the mixture of 2-hydroxy-5-methoxybenzaldehyde, potassium carbonate and dimethyl sulfate as in Example 1 at room temperatures the reaction was completed in 7 days. This was confirmed by gas chromatography. By treating the reaction mixture as described in Example 1, 44.5 g of 2,5-dimethoxybenzaldehyde having a melting point of 47°C were obtained (Yield: 81.5%).
Example 4 - By repeating the procedures described in Example 1 except that 31 g of diethyl sulfate were used instead of 50 g of dimethyl sulfate, 53 g of 2-ethoxy-5-methoxybenzaldehyde having a melting point of 47-48°C were obtained (Yield: 97.5%).
Abstract - A process for preparing 2-alkoxy-5-methoxybenzaldehyde, said alkoxy group being a methoxy or an ethoxy group, which comprises reacting, in the presence of potassium carbonate, 2-hydroxy-5-methoxybenzaldehyde with a dialkyl sulfate, said alkyl group being a methyl or an ethyl group, is enclosed.
Example 1 - 50 g of 2-hydroxy-5-methoxybenzaldehyde, 68 g of potassium carbonate and 50 g of dimethyl sulfate were refluxed in 250 mL of acetone for about 3 hours under stirring. After the reaction, the reaction mixture was filtered and the acetone was distilled off from the filtrate and then the residue was poured into 300 mL of water. The precipitated crystals were collected by filtration and dried whereby 45 g of 2,5-dimethoxybenzaldehyde having a melting point of 48°C were obtained (Yield: 82.5%).
Example 2 - On standing the mixture of 2-hydroxy-5-methoxybenzaldehyde, potassium carbonate and dimethyl sulfate as in Example 1 at room temperatures the reaction was completed in 7 days. This was confirmed by gas chromatography. By treating the reaction mixture as described in Example 1, 44.5 g of 2,5-dimethoxybenzaldehyde having a melting point of 47°C were obtained (Yield: 81.5%).
Example 4 - By repeating the procedures described in Example 1 except that 31 g of diethyl sulfate were used instead of 50 g of dimethyl sulfate, 53 g of 2-ethoxy-5-methoxybenzaldehyde having a melting point of 47-48°C were obtained (Yield: 97.5%).