Synthetic computer-assisted

The Frasca method for obtaining 1-arylindazoles also involves a C(3)—C(3a) ring closure (67CJC697). It consists in the cyclization of p-nitrophenylhydrazones of ketones and aldehydes with polyphosphoric acid. The Barone computer-assisted synthetic design program has found several new methods for preparing indazoles (79MI40409). The selected method involves the transformation of jV, jV -diphenylhydrazides (596) into 1-phenylindazoles (597) by means of trifluoromethanesulfonic anhydride. The yields vary from 2% (R = H) to 50% (R = Ph). 

This work has been carried out in association with Professor Elias J. Corey, who suggested the study of protective groups for use in computer-assisted synthetic analysis. 1 appreciate his continued help and encouragement. I am grateful to Dr. 

Corey EJ, Wipke WT, Cramer RD HI, Howe WJ. Computer-assisted synthetic analysis. Facile man-machine communication of chemical structure by interactive computer graphics. J Am Chem Soc 1972 94 421-30. 

We have already emphasized our view that the evaluation of chemical reactions and synthetic pathways is of preeminent importance in any system for computer-assisted synthesis design or reaction prediction. The quality of the evaluation process will determine to a large extent the overall quality of such a system. 

Even here, with well-established approaches, we see the influence of the information age. Employing computers to determine receptor structure and, thus, possible receptive blockers has become a useful tool in the drug discovery process. Computer-assisted drug synthesis has great potential. The revolution in this aspect of synthetic chemistry is analogous to the revolution that computers caused in the animation industry. Where once dozens of artists were necessary, computers have now replaced them, creating "life-like" animations that were not previously feasible. The same type of revolution will occur in the chemical drug synthetic industry. 

After introducing the algorithm for strategic bond selection developed in connection with "computer-assisted synthetic analysis" (see Part B), we can now return to the use of radical intermediates in the synthesis of monocyclic (and polycyclic) compounds (see Heading 6.1.3). 

Wipke, W. T. "Computer-Assisted Three-Dimensional Synthetic... 

Wipke, W. T. "Computer-Assisted Three-Dimensional Synthetic Analysis . In Computer Representation and Manipulation of Chemical Information Wipke, W. T. Heller, S. R. Feldmann, R. J. Hyde, E., Eds. John Wiley and Sons, Inc. 1974, pp 147-174. 

Wong, G., Koehler, K.F., Skolnick, P., Gu, Z.-Q., Ananthan, S., Schonholzer, P., Hunkeler, W., Zhang, W., and Cook, J.M. Synthetic and computer-assisted analysis of the structural requirements for selective, high-afhnity ligand binding to diazepam-insensitive benzodiazepine receptors./. Med. Chem. 1993, 36, 1820-1830. 

Corey EJ, Long AK, Greene TW, Miller JW. Computer-assisted synthetic analysis. Selection of protective groups for multistep organic syntheses. J Org Chem 1985 50 1920-1927. 

Corey EJ, Wipke WT, Cramer RD, Howe WJ (1972) Computer-assisted synthetic analysis. Facile man-machine communication of chemical structure by interactive computer graphics, J Am Chem Soc 94/2 421 Wipke WT, Braun H, Smith G, Choplin F, SieberW (1977) SECS — Simulation and evaluation of chemical synthesis Strategy and planning, in Computer-assisted organic synthesis, Wipke WT, Howe WJ ed, ACS Symposium Series, p 98... 

Organic Syntheses. E. J. Corey, W. T. Wipke, R. D. Cramer, and W. J. Howe,/. Am. Chem. Soc., 94, 421 (1972). Computer-Assisted Synthetic Analysis. Facile Man-Machine Communication of Chemical Structure by Interactive Computer Graphics. E. J. Corey, W. T. Wipke, R. D. Cramer, and H. J. Howe,/. Am. Chem. Soc., 94, 431 (1972). Techniques for Perception by a Computer of Synthetically Significant Structural Features in Complex Molecules. 

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