Of mephenesin

Procedure Weigh accurately 0.15 g of mephenesin and dissolve in 50 ml of DW into a 250 ml iodine-flask. Add to it 25.0 ml of 0.1 N potassium bromate solution and 10.0 g of powdered potassium bromide. After the dissolution of KBr, add 10 ml of hydrochloric acid, insert the moistened stopper, and after 10 seconds add 10 ml of potassium iodide solution. Titrate with 0.1 N sodium thiosulphate using starch solution as indicator. Each ml of 0.1 N potassium bromate is equivalent to 0.00911 g of C10H,4O3. 

A 43-year-old woman, who ingested between 5.5 and 11 g of mephenesin recovered within about 10 hours following treatment (D. W. Barron and T. G. Milliken, Lancet, 1960,1, 262). 

Mephenesin is a drug used as a mu.scle relaxant and sedative. Propose a synthesis of mephenesin from benzene and any other reagents needed. 

Methocarbamol was developed in 1956 in the laboratories of A.H. Robins. Studies were directed towards the development of propanediol derivatives which possessed muscle relaxant properties superior to those of mephenesin, which had low potency and a short duration of action1 >2,3. 

Its actions are similar to those of mephenesin. The duration of action ranges between 4 to 6 hours. It is usually employed for the symptomatic relief of muscular spasm. 

The enantiomers of Mephenesin are shown separated in figure 11.13 (A) on a stationary phase consisting of coated cellulose derivatized with tris(3,5-dimethylphenylcarbamate). A mixture ofw-hexane/2-propanol/diethyl-amine 80/20/0.11 v/v/vwas used as the mobile phase. In figure 11.13 (B), which shows the separation of the enantiomers of Tolperisone, the stationary phase was cellulose derivatized with tris(3,5-difluoro-phenylcarbamate) and a mixture of -hexane/2-propanol 90/10 v/v was used as the mobile phase. 

Koda A, Shimazawa T, Watanabe S, Yanagihara A (1972) Anti-allergic effect of nicotinic acid derivatives and related compounds of Mephenesin. Jpn J Pharmacol 22 111 Komer WF, VoUm J (1976) In Klinische Pharmakologie und Pharmakotherapie. Urban Schwarzenberg, Munich Berlin Vienna... 

Compounds (XXVI) and (XXVII) were reported to have about the same order of muscle relaxing effect in the mouse and cat as chloromezanoneP . Esterification of mephenesin with... 

Thus the new metabolic conversion involving introduction of nitrogen which was found for the first time in the metabolism of Mephenesin, 3-(o -tolyloxy)-1,2-propanediol, was shown to occur also in the metabolism of the above two compounds. 

Mephenesin, 3-( -tolyloxy)- ,2-propanediol, undergoes hydroxylation on the aromatic ring (1) and oxidation of the C -alcoholic hydroxyl group to form 3- -tolyloxylactic acid, which is the major metabolite of Mephenesin (2,3). 

N-Acetyl-6-( -tolyloxy)alanine as well as 3-( -tolyloxy)lactic acid are major metabolites of Mephenesin. In the rats treated with 3-( -tolyloxy)-l, 2-propanediol and 3-phenoxy-l, 2-propanediol, the N-acetyl-3 aryloxyalanine was not as abundant as the 3 aryloxy-lactic acid. However, the new metabolic conversion involving introduction of nitrogen was confirmed to occur also for the two Mephenesin analogues. 

IDENTIFICATION OF N-ACETYL-j3-ARYLOXYALANINES FROM RATS in the case of Mephenesin (4). 

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