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Biochemistry for medical students. 6th ed. By W. V. Thorpe. J. B. Lippincott Company, Philadelphia, 1956. viii + 542 pp. 14.5 × 21 cm. Price $6.75
A Note on the Synthesis of Pyrrole-2-carboxylic Acid* By E. E. SMISSMAN,t M. B. GRABER, and R. J. WINZLER
I
of sialic acid (1, 2) isolated from submaxillary mucin and other sources, one of the principal products obtained is pyrrole-2carboxylic acid. In this laboratory it was desired t o obtain this pyrrole acid for comparison with sialic acid and degradation products isolated by a different procedure. Several methods for its preparation are reported in the literature (3, 4) but either the yields were low or the reactions gave a mixture of both the 2- and 3-carboxylic acids. In an attempt to secure a method which would afford higher yields of a pure product, high pressure carboxylation of pyrrole was tried and afforded a 53y0yield of pure pyrrole-2-carboxylic acid. N THE DEGRADATION
EXPERIMENTAL
Six and seven-tenths grams (0.1 mole) of freshly distilled pyrrole was added to a mixture of 100 ml. water and 50 Gm. (0.5 mole) of potassium carbonate in a 300-ml. steel reaction vessel.' The vessel was sealed and carbon dioxide was introduced to a pressure of 900 p. s. i. The reaction vessel was shaken for five minutes a t room temperature during which time a n initial pressure drop of 325 p. s. i. was observed. The vessel was repeatedly recharged and shaken for five-minute intervals until a
* Received November 17, 1955, from department of Biochemistry, College of Medicine, University of Illinois, Chicago. t Present address: University of Wisconsin School of Pharmacy, Madison. American Instrument Company, Silver Spring, Maryland.
constant pressure reading of 800 p. s. i. was obtained. The temperature of the vessel was elevated to 100" and maintained at this temperature while shaking the vessel for three hours. The reaction mixture was filtered and the vessel washed with 100 ml. of water and the washings passed through the filter. The combined filtrates were heated to boiling with 0.5 Gm. of charcoal, filtered, and cooled t o &5'. The solution was acidified t o PH 2-3 with concentrated hydrochloric acid. This process required rapid agitation and cooling. The acidified mixture was cooled to 0" and the acid and mixed salts were removed immediately by filtration. The solid material was mixed with 100 ml. water and concentrated ammonium hydroxide was added until the material had dissolved. The solution was heated to boiling and 0.25 Gm. of charcoal was added. The solution was filtered, cooled t o 0-5" and acidified with concentrated hydrochloric acid to pH 2-3. The solution was cooled to 0' and filtered immediately t o give a white, crystalline solid, m. p. 197-98" decompn. [lit. 192' decompn. (4)], yield 5.2 Gm. (53.6y0,). Mixed m. p. 196-197" decompn. REFERENCES (1) Klenk, E., and Lowenstein, K., 2. physioi. Chem.. 291, 147(1952). (2) Utsushi, M., Tohoku, I.,Exptl. Med. and Sarg., 51, 319( 1949). (3) Ciamician. G., and Silber P. Bey. 17 1151(1884). (4) McCay, C., and Schmid;, Cl, J . km.' Chem. Soc., 48, 1933 (1926).
Book Notices Biochemistry f o r Medical Students. Gth ed. By W. V. THORPE.J. B . Lippincott Company, Philadelphia, 1956. viii 4- 542 pp. 14.5 x 21 cm. Price $6.75. This book represents a revision of a standard textbook on biochemistry. The major additions t o the 6th edition relates to protein structure, enzyme A and its role in metabolic processes. The entire chapter on enzymes has been thoroughly revised and contains much essential new information on this subject. In addition, the material on nucleic acids has been rewritten and the subject of redox potentials has been brought up t o date. The bibliography is adequate for the purpose intended and includes references t o recently published works.
Actualitis Pharmacologiques. Published under the direction of RENE HAZARD.Masson et Cie., Paris, 1955. 198 pp. 16.5 x 25 cm. Price 1.480 fr. This volume in the pharmacology series that was started in 1949 continues t o present (in French) discussions on new groups of medicinals, their mode of action and theoretical and practical considerations of the pharmacodynamic problems involved. The text is composed of seven papers by different authors and are titled: adrenaline and noradrenaline synthetic tuberculostatics; antibiotics obtained from higher plants; lysis and the inversion of the tensional effects of adrenaline; pharmacodynamics of theophylline and its derivatives; comparative study
I
of sialic acid (1, 2) isolated from submaxillary mucin and other sources, one of the principal products obtained is pyrrole-2carboxylic acid. In this laboratory it was desired t o obtain this pyrrole acid for comparison with sialic acid and degradation products isolated by a different procedure. Several methods for its preparation are reported in the literature (3, 4) but either the yields were low or the reactions gave a mixture of both the 2- and 3-carboxylic acids. In an attempt to secure a method which would afford higher yields of a pure product, high pressure carboxylation of pyrrole was tried and afforded a 53y0yield of pure pyrrole-2-carboxylic acid. N THE DEGRADATION
EXPERIMENTAL
Six and seven-tenths grams (0.1 mole) of freshly distilled pyrrole was added to a mixture of 100 ml. water and 50 Gm. (0.5 mole) of potassium carbonate in a 300-ml. steel reaction vessel.' The vessel was sealed and carbon dioxide was introduced to a pressure of 900 p. s. i. The reaction vessel was shaken for five minutes a t room temperature during which time a n initial pressure drop of 325 p. s. i. was observed. The vessel was repeatedly recharged and shaken for five-minute intervals until a
* Received November 17, 1955, from department of Biochemistry, College of Medicine, University of Illinois, Chicago. t Present address: University of Wisconsin School of Pharmacy, Madison. American Instrument Company, Silver Spring, Maryland.
constant pressure reading of 800 p. s. i. was obtained. The temperature of the vessel was elevated to 100" and maintained at this temperature while shaking the vessel for three hours. The reaction mixture was filtered and the vessel washed with 100 ml. of water and the washings passed through the filter. The combined filtrates were heated to boiling with 0.5 Gm. of charcoal, filtered, and cooled t o &5'. The solution was acidified t o PH 2-3 with concentrated hydrochloric acid. This process required rapid agitation and cooling. The acidified mixture was cooled to 0" and the acid and mixed salts were removed immediately by filtration. The solid material was mixed with 100 ml. water and concentrated ammonium hydroxide was added until the material had dissolved. The solution was heated to boiling and 0.25 Gm. of charcoal was added. The solution was filtered, cooled t o 0-5" and acidified with concentrated hydrochloric acid to pH 2-3. The solution was cooled to 0' and filtered immediately t o give a white, crystalline solid, m. p. 197-98" decompn. [lit. 192' decompn. (4)], yield 5.2 Gm. (53.6y0,). Mixed m. p. 196-197" decompn. REFERENCES (1) Klenk, E., and Lowenstein, K., 2. physioi. Chem.. 291, 147(1952). (2) Utsushi, M., Tohoku, I.,Exptl. Med. and Sarg., 51, 319( 1949). (3) Ciamician. G., and Silber P. Bey. 17 1151(1884). (4) McCay, C., and Schmid;, Cl, J . km.' Chem. Soc., 48, 1933 (1926).
Book Notices Biochemistry f o r Medical Students. Gth ed. By W. V. THORPE.J. B . Lippincott Company, Philadelphia, 1956. viii 4- 542 pp. 14.5 x 21 cm. Price $6.75. This book represents a revision of a standard textbook on biochemistry. The major additions t o the 6th edition relates to protein structure, enzyme A and its role in metabolic processes. The entire chapter on enzymes has been thoroughly revised and contains much essential new information on this subject. In addition, the material on nucleic acids has been rewritten and the subject of redox potentials has been brought up t o date. The bibliography is adequate for the purpose intended and includes references t o recently published works.
Actualitis Pharmacologiques. Published under the direction of RENE HAZARD.Masson et Cie., Paris, 1955. 198 pp. 16.5 x 25 cm. Price 1.480 fr. This volume in the pharmacology series that was started in 1949 continues t o present (in French) discussions on new groups of medicinals, their mode of action and theoretical and practical considerations of the pharmacodynamic problems involved. The text is composed of seven papers by different authors and are titled: adrenaline and noradrenaline synthetic tuberculostatics; antibiotics obtained from higher plants; lysis and the inversion of the tensional effects of adrenaline; pharmacodynamics of theophylline and its derivatives; comparative study