From Trevor Laird, the distinguished editor of Organic Process Research and Development, a poem on what chemistry the editors of OPR&D would like to see. Quoting from the middle of the poem:
...But sometimes my enthusiasm stops
At work ups with bunches of ops,
Or by poor separations,
Numerous crystallisations
(I prefer to see direct drops).
So writers of manuscripts note,
Our referees may ponder and vote
To reject your paper
If you don’t taper
Operations that will “get my goat”.
Product isolation isI think this poem reminds the novice process chemist that the nature of the waste streams coming from processes is just as important (and related to!) the inputs into the process. While you tend to think (from a development POV) about the reagents that go into the process, the cost of disposing of waste streams can sometimes be a deal breaker.
As important as synthesis.
A large number of streams
Of effuents means
Your process is most likely a miss...
From the word go we tried to recycle solvents. I used the same THF about75 times, just replacing the losses. We analysed to ensure there were no impurities accumulating.
ReplyDeleteSolvent recovery was considered too expensive.
Waste water was checked by the ecology services and poured down the drain to the water purification system. Any inorganics we usually precipitated and incinerated.
As we moved into production this aspect of the process was optimized as much as the actual chemistry to produce the drug substance.
Kinda lame.
ReplyDeleteDear Anonymous 8:48am, pray elaborate, what is "Kinda Lame"?
ReplyDeleteThe poetry, my dear man, the poetry.
DeleteWell is it Trevor Laird that wrote it!
Delete