Preparation of 2,3-dihydroxy-3-phenylpropanoic acid
60 g of cinnamic acid are dissolved in 5 to 6 litres of water and the solution made strongly alkaline with sodium carbonate or caustic soda. It is then cooled with ice, and treated slowly, and with continual stirring and cooling, with 90 g of potassium permanganate in 2%, aqueous solution. During the oxidation the temperature should not rise above 0° C. The solution is filtered from precipitated manganese hydroxide, and dilute hydrochloric acid added to the clear filtrate until it is only slightly alkaline. It is then boiled down to about half its volume, neutralised with hydrochloric acid, and concentrated on the water-bath to a small volume. A good deal of salt separates out, but this does not interfere with the isolation of the acid. After cooling, the solution is repeatedly extracted with ether (eight to ten times). The ethereal extracts are extracted with cold water and the dissolved ether removed from the aqueous portion by blowing air through it. A slight precipitate separates and is discarded. The filtrate is heated almost to boiling and neutralised with chalk. On cooling, the calcium salt of 2,3-dihydroxy-3-phenylpropanoic acid separates out and is purified by recrystallisation. The free acid can be obtained by decomposing the calcium salt with hydrochloric acid and then extracting with ether. As, however, the acid is very soluble in water and only slightly soluble in ether, it is better to decompose the calcium salt with the exact amount of oxalic acid, filter off the calcium oxalate, and concentrate the filtrate until crystallisation sets in. The acid crystallises from water in colourless needles which melt with decomposition at 141° C.
Preparation of organic compounds, E. de. Barry Barnett, 97, 1912
2,3-dihydroxy-3-phenylpropanoic acid, 56816-80-9, NSC102080, AC1Q5SRB, AC1L6EM2, Oprea1_302742, Oprea1_623987, IFLab1_004151, SCHEMBL3192877, CTK5A5742, BNOUUNAFHCJIJD-UHFFFAOYSA-N, HMS1423M15, AR-1D2575, NSC102081, 2,3-Dihydroxy-3-phenylpropionic acid, AKOS002161981, AKOS016290071, 2,3-dihydroxy-3-phenyl propanoic acid, NSC-102080, NSC-102081, OR184381, OR227354, Propionic acid, 2,3-dihydroxy-3-phenyl-, ST50036756, Benzenepropanoicacid, a,b-dihydroxy-, (aR,bR)-rel-, F0848-0333, BENZENEPROPANOIC ACID, A,B-DIHYDROXY-, (AR,BS)-REL-, 16088-08-7, 5695-95-4
2,3-Dihydroxyphenylpropionic acid, CID265740, 3714-73-6, 57230-00-9