# Is there a way to oxidize salicyl alcohol to salicylic acid without using chromium trioxide? [closed]

I'm doing a project for school and I need to convert salicyl alcohol to salicylic acid, but I'm not allowed to use $$\ce{CrO3}$$ because of its toxicity. I know it is also possible to oxidize a primary alcohol to a carboxylic acid with potassium permanganate, but I read it might be a too strong oxidizer. Is there any good alternative?

• @IvoFilot Please don't use something like CrO$_3$ as it may break in some browsers (especially with the responsive design); instead use the mhchem macro $\ce{CrO3}$. More detail on meta: here and here. We also usually do not correct Brittish spellings (if used consistently), because that has lead to edit wars in the past. In any case: Thanks for your effort. Nov 13 '18 at 14:14
• Hmm, I think there are too many ways... Nov 13 '18 at 19:38

Typical Procedure. A mixture of alcohol 1 ($$\pu{40 mmol}$$), TEMPO ($$\pu{436 mg}$$, $$\pu{2.8 mmol}$$), $$\ce{MeCN}$$ ($$\pu{200 mL}$$), and sodium phosphate buffer ($$\pu{150 mL}$$, $$\pu{0.67 M}$$, $$\pu{pH = 6.7}$$) is heated to $$\pu{35 °C}$$. Then mixtures of $$\pu{9.14 g}$$ of 80% sodium chlorite ($$\ce{NaClO2}$$, $$\pu{80.0 mmol}$$) in $$\pu{40 mL}$$ of water and 2.0 mol% dilute bleach ($$\pu{1.06 mL}$$ of 5.25% $$\ce{NaOCl}$$ diluted into $$\pu{20 mL}$$ with water) are added simultaneously over $$\pu{2 h}$$ (Caution! Do not mix bleach and $$\ce{NaClO2}$$ before being added to the reaction mixture). The mixture is stirred at $$\pu{35 °C}$$ until the reaction is complete (<2% starting material, $$\pu{2−5 h}$$ reaction time), then cooled to room temperature. Water ($$\pu{300 mL}$$) is added, and the $$\mathrm{pH}$$ is adjusted to $$8.0$$ with $$\pu{2.0 N}$$ $$\ce{NaOH}$$ (about $$\pu{48 mL}$$). The reaction is quenched by pouring into cold ($$\pu{0 °C}$$) $$\ce{Na2SO3}$$ solution ($$\pu{12.2 g}$$ in $$\pu{200 mL}$$ of water) maintained at $$\pu{<20 °C}$$. The $$\mathrm{pH}$$ of the aqueous layer should be $$8.5$$$$9.0$$. After stirring for $$\pu{0.5 h}$$ at room temperature, methyl tert-butyl ether (MTBE, $$\pu{200 mL}$$) is added. The organic layer is separated and discarded. More MTBE ($$\pu{300 mL}$$) is added, and the aqueous layer is acidified with $$\pu{2.0 N}$$ $$\ce{HCl}$$ (~$$\pu{100 mL}$$) to $$\pu{pH = 3−4}$$. The organic layer is separated, washed with water ($$2 \times \pu{100 mL}$$) and brine ($$\pu{150 mL}$$), and then concentrated to give the crude carboxylic acid 2 in 85−100% yield. The products may be purified by silica gel column chromatography or crystallization.