Alpha eucaine

The bicyclic tropane ring of cocaine of course presented serious synthetic difficulties. In one attempt to find an appropriate substitute for this structural unit, a piperidine was prepared that contained methyl groups at the point of attachment of the deleted ring. Condensation of acetone with ammonia affords the piperidone, 17. Isophorone (15) may well be an intermediate in this process conjugate addition of ammonia would then give the aminoketone, 16. Further aldol reaction followed by ammonolysis would afford the observed product. Hydrogenation of the piperidone (18) followed then by reaction with benzoyl chloride gives the ester, 19. Ethanolysis of the nitrile (20) affords alpha-eucaine (21), an effective, albeit somewhat toxic, local anesthetic. 

Allobarbital, 269 Allopurinol, 152, 426, 427 Allylestrenol, 172 Aloxidone, 232 Alpha eucaine, 8 Alphaprodine, 303, 304, 305 Alprenolol, 117 Althizide, 359 Ambucaine, 11 Ambucetamide, 94 Amidoquine, 342 Amiloride, 278 Aminitrazole, 247 7-Aminocephalosporanic acid (7-ACA), 416, 417 Aminoglutethemide, 257... 

Figure 20-2 The incorrect structures proposed for cocaine (a) and tropine (b) by Albert Einhorn and Georg Merling. Structures of methyltrlacetone alkamine (c). alpha-Eucaine (d). and beta-Eucaine (e).

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