Phenols and anilines are two of the most important building blocks in industrial chemical manufacturing. Any process capable of converting one into the other is going to generate a lot of interest, and a paper by Shi and co-workers does just that.1 Direct conversion of an aniline to a phenol is a relatively straightforward transformation

Process chemists at Genentech recently published their work on development of a kilo-scale synthesis of JAK-1 inhibitor- GDC-4379 (Figure 1).1The central heterocyclic core of the molecule consists of a 4-aminopyrazole moiety (elaborated as the pyrazolopyrimidene amide- presumably the inhibitor hinge binding fragment in the kinase active site) with an additional aryl substituent at C-3 and

Oxidation of allylic alcohols to enones, although on paper a simple reaction, usually requires insidiously toxic metals or metalloids such as chromium and selenium or hazardous peroxy- reagents.1 Scale-up of these methods remains particularly challenging. A team from GSK found themselves in precisely this position when developing a synthetic route to a steroid-derived HIV maturation

The importance of methylation in the discovery and development of bio-active small molecules is well known. I presented a webinar a couple of years ago on the “The magic methyl in medicinal chemistry,” demonstrating the unique properties of this, the simplest functional group.1 I also reviewed the state of the art in synthetic approaches to

Perhaps the best-known ring-expansion reaction is the Baeyer-Villiger oxidation, first reported in 1899- not surprisingly by Adolf von Bayer and Victor Villiger. As we’re all aware, reaction of a carbonyl with a peracid generates a Criegee-type intermediate that undergoes rate-limiting concerted rearrangement to form an ester or lactone. The migration order is substituent dependant, with

The first electrophilc aromatic substitution reaction you were taught as an undergraduate was almost certainly nitration.1 Nitration and subsequent reduction of the aryl nitro group to an aniline via high temperature metal catalysed hydrogenation remains an important industrial process. The reduction has many flavours- both in terms of the substitution pattern on the aryl (and

The ability to handle gaseous reagents presents a number of challenges for synthetic chemists. The problem becomes particularly acute when scaling up biphasic (liquid/gas) or even triphasic (gas/liquid/solid) systems due to limiting mass transfer effects. Pressure vessels or autoclaves are also not always practical and easy to come by. A practical solution to this (if

Many years ago, I heard an anecdote regarding a fortuitous discovery in the Sharpless lab. A graduate student had been awarded their PhD and the group were celebrating in the lab with bottles of red wine (I know- but they were different times). Someone in the group-who had obviously consumed a sufficient quantity of the

In March 1989, two chemists, Stanley Pons and Martin Fleishmann, stunned the world by claiming that an electrical current from a palladium electrode immersed in a test tube of water had resulted in nuclear ‘cold fusion’ at room temperature.1 For many years, attempts to understand and reproduce this seemingly impossible result- with sketchy information from

Back in August I posted a scheme for the synthesis of a late-stage intermediate towards PF-06826647, a compound identified by Pfizer as a potent and selective tyrosine kinase 2 (TYK-2) inhibitor. I asked if you could identify reagents or intermediates A, B and D. Below are the answers! You can read more here in the full