Phenylacetic add

The obvious way is to indude p-phenylacetic add or p-phenylethylamine in cultures. Indeed, when (J-phenylacetic add was added to cultures grown in CSL, the yields of penidllin were enhanced further. Typical yields were 100-150 ig ml 1. 

You may for example have suggested that the supply of other nutrients, such as ammonia and O2, may be adjusted to respond to the different needs of growth and penicillin production. You may also have suggested that precursors of specific penicillins, such as P-phenylacetic add, may be added after the growth phase is complete. You may have also considered altering physical parameters such as pH and temperature. 

You should have identified that the acyl moiety, phenylacetic add, is the second product arising from the hydrolysis of penicillin G. This could be recovered from the reaction mixture and reused as a precursor for penicillin G production. In practice, an integrated process is used. We can represent this in the following way ... 

Penicillin G production can be encouraged by adding fi-phenylacetic add to the medium. This was described in the text and will not be elaborated upon here. 

The obvious addition to produce penicillin X is pOHfl-phenylacetic add. 

This could be derived from tyrosine via the amine derivative, in a process similar to the production of P-phenylacetic add in CSL. 

Various diastereoselective Michael reactions are based on y-bromo-, y-alkyl-, or y-alkoxy-2(5//)-furanones following the trans-face selectivity shown in Section 1.5.2.3.1.2. Thus the lithium enolates of esters such as ethyl propanoate, ethyl a-methoxyacetate and ethyl a-phenylacetate add to methoxy-2(5/f)-furanone with complete face selectivity269-273 (see Section 1.5.2.4.4.2.). 

Hydrolysis of benzyl cyanide to phenylacetamide. In a 1500 ml. three-necked flask, provided with a thermometer, reflux condenser and efficient mechanical stirrer, place 100 g. (98 ml.) of benzyl] cyanide and 400 ml. of concentrated hydrochloric acid. Immerse the flask in a water bath at 40°. and stir the mixture vigorously the benzyl cyanide passes into solution within 20-40 minutes and the temperature of the reaction mixture rises to about 50°. Continue the stirring for an additional 20-30 minutes after the mixture is homogeneous. Replace the warm water in the bath by tap water at 15°, replace the thermometer by a dropping funnel charged with 400 ml. of cold distilled water, and add the latter with stirring crystals commence to separate after about 50-75 ml. have been introduced. When aU the water has been run in, cool the mixture externally with ice water for 30 minutes (1), and collect the crude phenylacetamide by filtration at the pump. Remove traces of phenylacetic add by stirring the wet solid for about 30 minutes with two 50 nd. portions of cold water dry the crystals at 50-80°. The yield of phenylacetamide, m.p. 154-155°, is 95 g. RecrystaUisation from benzene or rectified spirit raises the m.p. to 156°. 

The synthesis of a-aryl esters can be achieved through the reaction of aryl and heteroaryl halides with CH2C02Bu-t, CHMeC02Bu-t and CHPhC02Lt ions under photoinitiation in 57-89% yields [20]. Moreover, phenylacetic add dianion reacts with ArX upon irradiation to give aryl substitution produds at the p- or a-carbon, depending on the counterion used (Scheme 10.9) [21]. 

Nwokogu, G.C., Wong, J.-W., Greenwood, T.D. and Wolfe, J.F. (2000) Photostimulated reactions of phenylacetic add dianions with aryl halides. Influence of the metallic cation on the regiochemistry of arylation. Organic Letters, 2, 2643—2646. 

The enolate of methyl phenylacetate adds to a second molecule of methyl phenylacetate to form the Claisen intermediate that is pictured. Elimination of methoxide (circled) and acidification give the product shown. 

The only method of preparative interest is the condensation of phenylacetic add and cinnamic aldehyde. The aboye procedure follows the method of Kuhn and Winterstein. Bistyryl has been obtained also from styrylmagnesium bromide and cupric chloride. ... 

The results obtained by the addition of p-phenylacetic add to cultures suggest a method of produdng a wide variety of penidllins. See if you can explain what this is. 

Cleavage with dilithium biphenylide in THF gave, on carbonation triphenylacetic acid in 93% yield and detectable phenylacetic add. ... 

This is a way to do this procedure without having to use one of those crazy tube furnaces stuffed with thorium oxide or manganous oxide catalyst [21]. The key here is to use an excess of acetic anhydride. Using even more than the amount specified will insure that the reaction proceeds in the right direction and the bad side reaction formation of dibenzylketone will be minimalized (don t ask). 18g piperonylic acid or 13.6g phenylacetic add, 50mL acetic anhydride and 50mL pyridine are refluxed for 6 hours and the solvent removed by vacuum distillation. The remaining residue is taken up in benzene or ether, washed with 10% NaOH solution (discard the water layer), and vacuum distilled to get 8g P2P (56%). 

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