1998 Progress Report: Environmental Hazard Assessment for Computer-Generated Alternative SynthesesEPA Grant Number: R825329
Title: Environmental Hazard Assessment for Computer-Generated Alternative Syntheses
Investigators: Hendrickson, James B.
Institution: Brandeis University
EPA Project Officer: Hahn, Intaek
Project Period: October 15, 1996 through September 14, 1999
Project Period Covered by this Report: October 15, 1997 through September 14, 1998
Project Amount: $275,235
RFA: Technology for a Sustainable Environment (1996) RFA Text | Recipients Lists
Research Category: Sustainability , Pollution Prevention/Sustainable Development
Objective:The objective of this research project is to provide a fully operational version of the SYNGEN program for the rapid generation of all the shortest synthetic routes to any organic compound, with an assessment of the environmental hazards associated with the chemicals used in each route, as well as a projection of its cost.
Progress Summary:Much of the presentation interface for the user?the input and output graphics?was done in the first year. In the current period, the central part of the project is the rebuilding of the SYNGEN program itself. A number of things have made this mandatory. First, the incorporation of sorting routes by environmental hazard assessment required changes in the program flow that were not properly compatible with the way it had been written before. Furthermore, the considerable growth in speed and capacity of current computers has made possible a broader scope for the route generations to include a number of options that we always had projected but could not implement on the older computers. These include, for example, more flexible skeleton dissection than was allowed before and, hence, different handling of the subsequent reaction generation.
This expansion in the range of the program has led to changing its basic generational philosophy from a breadth-first flow of the operations to a depth-first one to more efficiently accommodate these broader requirements. Dr. Parks has taken advantage of this revision to write more succinct and general modules, and to document more clearly for future expansions or alterations of the SYNGEN program. This improvement in maintainability greatly will enhance our ability to add new options in the future, especially extensions of the environmental hazard assessments.
In another area, the original starting materials catalog has been expanded from about 4,500 compounds in the original SYNGEN program to 25,592 entries in a rewritten catalog. Our new catalog entries were culled from the most complete collection of available chemicals worldwide, as provided by the Available Chemicals Directory (ACD) from MDL Systems, Inc. The ACD entries were surveyed; those with full data on price and CAS index number were then compared with our criteria of size and price, changed into our own maximal structural notation, and incorporated into the new SYNGEN catalog. These entries are annotated with our unified environmental hazard ratings. The third area involves the linking of SYNGEN to the literature to validate the reactions that it generates. For this purpose, an expanded COGNOS database of reactions has been culled for its construction reactions (over 100,000), and these have been ordered into a special viewing program to assess the numbers and average yields of the various families of constructions that will become the validation table for reactions generated in SYNGEN. These currently are being examined to make sure that they provide a realistic comparison for the reaction families used in SYNGEN.
Future Activities:The SYNGEN program revision will be completed and connected to the new catalog of starting materials as well as the input and output graphics for its user interface. The full program must then be extensively tested for accuracy and ease of use. The lookup table of reaction precedents from the literature, taken from the expanded COGNOS database, also will be incorporated, and its results and presentation assessed.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
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||Hendrickson JB. Building the shortest synthesis route. Chemtech 1998;28(9):35-40||