kilomentor | 11 February, 2007 15:41
In the opinion of Kilomentor, the most under appreciated and under utilized method of separation that can be used in chemical process development is dissociation extraction. Dissociation extraction crystallization and dissociation leaching are two powerful variations on this same method. Fractional crystallization, which is hardly every used, in practice is frequently mentioned while this method, which is more frequently applicable, is effectively unknown.
kilomentor | 08 February, 2007 05:54
kilomentor | 04 February, 2007 10:29
As one scales up a chemical process development step, one of the potential problems that I have found it difficult to foresee is emulsion formation. In about 40 years of experience the single most frequent cause for a call in the night from the pilot plant production management is an unpredicted emulsion, which interferes with a separation of two liquid phases. When one of these emergencies occurs, it is a blessing to have whatever you know about solving the problem assembled in a single place, because quite a few people are waiting for your instructions.(More)
kilomentor | 02 February, 2007 06:20
Chemical transformations and chemical separations are the building blocks of process synthesis. It is chemical transformations that create the reaction intermediates that connect postulated starting materials to desired final product. What information might we have as pointers to decide how to achieve a conversion:
kilomentor | 24 January, 2007 18:26
Creating rugged scaleable processes has always been important for process chemistry. Exploratory and early development small scale reactions are most frequently purified using chromatography, but chromatography is not readily scaled up and it is expensive. Larger scale requires more rationally selected purification methods. A goal of this presentation is to show how using sulfuric acid esters can efficiently and economically improve preparative scale organic synthesis.(More)
kilomentor | 24 January, 2007 17:58
I have proposed that a synthetic chemist can assess the relative merits of two or more routes of synthesis by looking at the proposed intermediates in the schemes and rating the likelihood that they can be separated cleanly and in good yield. Schemes that have a higher proportion of these preferred intermediates on balance are more promising. One intermediate that I propose that you can depend upon being readily isolated and efficiently purifiable is salts of organic acids and bases. Below I would like to may a variety of points which all apply to using salts of carboxylic acids as dependable intermediates.(More)
kilomentor | 21 January, 2007 12:58
The Goal of the Kilomentor Blog is to build up a body of information over time, which can be alternately described as:
I am a graduate from Harvard University and have worked for more than 40 years as a pharmaceutical process chemist in Canada and the United States. My motivation is to remove every barrier preventing chemists, anywhere that the world wide web reaches, from improving their process chemistry talents. Just search the keyword kilomentor!
kilomentor | 19 January, 2007 06:03
Based on an examination of what really goes on in a chemical process step a method of rating the difficulties of the separation are proposed as a quantitative tool to rank the challenges of a process scale up.
Nature to be commanded must be obeyed.
In synthesis we talk about assembling, building or constructing a molecular structure. In an important aspect this is a misleading metaphor because we are comparing an activity in the nano-world to an activity in the macro world. Operating in the macroscopic world, as for example in building a house, we handle the pieces, we position the pieces, we join the pieces.(More)
kilomentor | 18 January, 2007 09:35
kilomentor | 04 January, 2007 15:07
kilomentor | 03 January, 2007 18:40
Any process has the possibility of continual incremental improvement but practically a point will be reached when it is not worth further effort and oneís time and talents are better expended elsewhere.(More)
kilomentor | 02 January, 2007 16:13
One key to imaginative and rugged chemical process development is extractive separations which are general for functional groups besides acids and bases. Many years ago now, a short paper was published which taught how to selectively extract only aldehydes. into water as areversible complex and thence isolate them.(More)
kilomentor | 30 December, 2006 18:55
kilomentor | 30 December, 2006 15:01
In organic chemistry, product isolation and purification is the most time consuming aspect of the art. It is the least intensively dealt with in the literature. Because preparative column chromatography is by far the most general and powerful of these methods, a thorough understanding of the available options is important. Over the years some highly refined and powerful methods have been designed for carrying out preparative scale separations; however, there has been no comprehensive description, tabulation or critical comparison of these second and third generation forms of preparative chromatography. This is the goal.(More)