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K.iura~roxLABORATORY ATD DEPARTMEST OF CHEMISTRT. USIVERSITY OF CALIFORNIA, ]1 BERKELEY
Small Scale Preparation of Carbon-14 Labeled Succinic, Malic, Fumaric and Tartaric Acids BY E. C. JOKGENSEN, J. A. BASSHAM, M, CALVIN AND B. 3'1. TOLBERT RECEIVED JULY 18, 1951 'Hie directions for preparing the following acids from labeled acetic acid on a twenty-millimole scale are presented: succinic acid, malic acid, fumaric acid and tartaric acid. Two methods for preparing the succinic acid are detailed.
On a twenty-millimole scale, succinic acid, labeled in either the one or two position, and rnalic acid, labeled in either the three or four position, with carbon-14 were prepared from the corresponding labeled acetic acids as2s3shown:
1
Although it has been reported that heating malic acid for various periods a t temperatures above 150" will give a mixture of products7~* including maleic acid and maleic anhydride in addition to the desired fumaric acid, these products were not observed in the chromato-
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inaric acid. Tests with inactive material showed * and +-these likely impurities llOzCCH2CHzCOzH would readily separate with The malic and succinic acids were separated by the solvents used and were not lost by volatilizadistribution between ether and water and one tion of the product from the paper. millimole of malic acid dehydrated to fumaric acid4 The osmium tetraoxide oxidation of malic acid which was then oxidized to tartaric acid5 has been shown to give a t least 99% pure tartaric acid.5 As expected the paper chromatograms and IIO~CCH~CHOHCO~H --+ radioautographs showed only one radioactive HCIOd compound in the purified product. IIO~C~H~CHOHCC~H
H
O~CEH=CHC O ~ H---+ H O&HOH os04
(1) Hz,Pt (2) H*0
CH OH C O ~ H
Experimental
Chloroacetic-l-C~4Acid.-Sodium acetate-l-Cl4 (1.15 g., 111 an alternate preparation of succinic acid, the 14 millimoles, specific activity 10 pc./rng.) was converted to following steps were used frcc acid and chlorinated as previously described.8J0 Ethyl Chloroa~etate-I-C~~.-The crude chloro* IICl(gj CIA, Ck[3COCI acetic acid from the previous steps was transferred CIIiCO.2 L ---+ CH~COzII -+ CIIfJE02H with a small amount of water (9 ml.) to a liquid1'4, I. liquid extractor and extracted with ether for 1.5 hours. At the end of this time the aqueous resiC2HSOH due was found t o contain only 0 3% of the original [ I j Sodium diethylin,()).
( 7 ) J. Peloure, A n n . , 11, 263 (1834). 18) J. Wielicenus, ibid., 846, 91 (1888). (9) 12. Ostwald J . B i d . C k c m . , 173, 207 (1948). (101 D.11. IIuglir
