General procedure for the synthesis of 3,4-dimethoxyphenylethanol from 3,4-dimethoxyphenylacetic acid: a dry and clean 100 mL round-bottomed flask was taken and sodium borohydride (0.4 g, 7.65 mmol) and iodine (1.3 g, 5.10 mmol) were accurately weighed and added to the flask, followed by the addition of 10 mL of tetrahydrofuran as solvent. The reaction vial was placed in an ice bath and stirred until homogeneous, then 3,4-dimethoxyphenylacetic acid (1.0 g, 5.10 mmol) was added slowly in 5 small portions. After the addition was completed, the ice bath was removed and the reaction was allowed to continue at room temperature. The progress of the reaction was monitored by thin layer chromatography (TLC). After about 30 minutes, TLC showed that the reaction was complete. To the reaction mixture, 50 mL of 5% sodium hydroxide solution was added and extracted with ethyl acetate (10 mL x 3), all organic phases were combined and washed with brine (10 mL x 3). The organic phase was separated, dried with anhydrous sodium sulfate, filtered and the solvent was evaporated to give 3,4-dimethoxybenzeneethanol (22) as a yellow oil in 98.9% yield.
[1] Patent: CN108484593, 2018, A. Location in patent: Paragraph 0050; 0051; 0065
[2] Journal of Organic Chemistry, 2010, vol. 75, # 15, p. 5289 - 5295
[3] Journal of Organic Chemistry, 2009, vol. 74, # 5, p. 2213 - 2216
[4] Journal of Organic Chemistry, 2004, vol. 69, # 7, p. 2362 - 2366
[5] European Journal of Organic Chemistry, 2008, # 27, p. 4622 - 4631