Arylaliphatic Compounds

The aromatic portion of the molecules discussed in this chapter is frequently, if not always, an essential contributor to the intensity of their pharmacological action. It is, however, usually the aliphatic portion that determines the nature of that action. Thus it is a common observation in the practice Ilf medicinal chemistry that optimization of potency in these drug classes requires careful attention to the correct spatial orientation of the functional groups, their overall electronic densities, and the contribution that they make to the molecule s solubility in biological fluids. These factors are most conveniently adjusted by altering the substituents on the aromatic ring. 

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Very well studied are arylaliphatic compounds ), especially those which have one double bond. By varying the ratio of carbonyl silane acid, the course of reaction can be immensely influenced. If the ratio is 1 1 10, only the double bond is hydrogenated ) whereas a mixture 1 3 10 hydrogenates both the double bond and the carbonyl function ). When this reducing combination is used in the former ratio, 3-benzoyl-butyric acid yields 4-phenyl-vaIeric acid (722), p.p -dinitrobenzophenone p,p -dinitrodiphenylmethane(123), l,6-diphenyl-hexane-l,6-di-one 1,6-diphenyl-hexane 124) and p-methoxybenzaldehyde p-methoxytoluene (725), respectively ). l,3-Diphenyl-l-propene-3-one gives (depending on the ratio ketone silane acid) 1,3-diphenyl-l-propanone (726) (1 1 10) and 1,3-diphenyI-propane (727) (1 3 10), respectively ). 

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