tag:blogger.com,1999:blog-43871000093413582842024-03-13T15:30:22.994+01:00Curly ArrowThis blog is devoted to the discussion of all aspects of synthetic organic chemistry and related sciences. Curly Arrow is run by a synthetic organic chemist based in Copenhagen, Denmark. Contributions from readers are always welcome and should be emailed to curlyarrow@gmail.comDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.comBlogger134125tag:blogger.com,1999:blog-4387100009341358284.post-19304686914419904402020-12-15T16:32:00.000+01:002020-12-15T16:32:41.854+01:00Green Peptide SynthesisSince my transition from academia to industry I have completely shifted my focus from medicinal chemistry and chemical biology to chemical process development for Phase 2 and 3 clinical trials. It has been a huge change and hard work getting up to speed but well worth it. As I am sure you can imagine switching you 50 ml RBF out with 1000 litre reactor potentially results in a massive Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com1tag:blogger.com,1999:blog-4387100009341358284.post-84512126728728816462019-12-20T16:04:00.000+01:002019-12-20T16:04:48.765+01:00Bitopic Ligands and Epoxides
For most academics, research can be a somewhat slow process. From the conception of an idea to actually getting started can take a significant amount of time. The topic of this post started as an idea based on Dror et al.'s publication back in 2011 that provided some strong in silico evidence for the presence of so-called metastable binding sites (MBS). Explained in very basic terms the Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com0tag:blogger.com,1999:blog-4387100009341358284.post-80716233734168158752019-12-20T13:51:00.000+01:002019-12-20T13:52:58.348+01:00Blog Comments Back On Line
I was wondering why no one ever seems to comment on the blog posts anymore and just discovered that I no longer get notified when someone submits a comment. ARghhh. I am really sorry about this. I have been through the long list of comments (and spam) and have posted stuff from the last couple of years just now. In the future I will see them as they come in and post them straight away. As I Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com0tag:blogger.com,1999:blog-4387100009341358284.post-76577612317428956142019-10-22T16:03:00.000+02:002019-10-22T16:03:58.411+02:00The Antistatic Portal
For a change I had to leave the office, put on a lab coat and go to the lab to weigh out some compound. I had a nice fluffy freeze dried substance that had to be transferred from one vial to another. I was faced with usual static electricity problem. The easy solution is to take your plastic gloves off and hope that your compound doesn't fly around the hood when you try to transfer it. Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-31436501169474841212018-06-26T16:11:00.000+02:002018-06-26T16:11:28.480+02:00The Disconnection Approach - Automated!
In my time as a synthetic organic chemist the most important advance in the field was definitely the introduction of searchable databases such as SciFinder and Reaxys. Life before these involved spending days on end in the library flipping though dusty tomes of chemical abstracts and Beilstein. And at the end you weren't even sure if you missed something of critical importance. The introductionDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-10474449278366534342018-06-21T09:48:00.001+02:002018-06-21T09:48:45.181+02:00Transfer of nasty stuff with a syringe and needle
Synthetic organic chemists often have to transfer something pyrophoric, toxic, volatile, smelly etc. from a commercially acquired sealed bottle such as a Sigma-Aldrich Sure/Seal bottle using a needle and syringe. Even with great care it has a tendency to drip from the needle tip, which is the last thing you are interested in. Now a Danish team has published a simple DIY solution that should be Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-78563295224872986792018-06-20T12:58:00.000+02:002018-06-20T13:59:52.805+02:00Quitting Academia
In my previous post I promised sharing my reasons for quitting academia. I just celebrated my 1 year anniversary in big pharma and boy did I make the right decision. So what was the problem for me? First of all my problem was not isolated to my geographical location. I have former academic colleagues all over the world and things are pretty much the same all over the place. In fact, relatively Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com4tag:blogger.com,1999:blog-4387100009341358284.post-62017640343922275112018-04-23T14:01:00.004+02:002018-04-23T14:03:14.363+02:00Industrial Postdoc in Chemical Development of Green Solid-Phase Peptide Synthesis
It's been awfully quiet here in recent years. However, you readers are still very active on the blog and it clearly continues to be a good resource for synthetic organic chemistry students, which is great. Last year I decided to say goodbye to my University career and move on to a position in the pharmaceutical industry. I've had a lot of questions regarding why I did so. It's a rather Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-31243907505225029052017-04-28T14:18:00.003+02:002017-04-28T14:19:21.956+02:00Catalytic Hydrogenation - A Farewell to Alcohol(s)
We have a project in my group on bitopic ligands targeting the adrenergic receptors. We recently published a perspective paper on the topic that you can check out here. Anyway, today we had a project meeting regarding the synthesis of bitopic salbutamol analogues.
To this end, one of the guys wanted to synthesise an epoxide as outlined above. However, to his (and everyone else surprise) evenDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com5tag:blogger.com,1999:blog-4387100009341358284.post-5153114464938327702017-03-01T16:43:00.003+01:002017-03-01T16:44:03.198+01:00Reproducibility!
I guess it is old news but it only caught my eye today at the BBC website. Apparently Nature did a survey last summer (2016) were scientist were asked if they had "failed to reproduce another scientist's experiments"? What really surprised me was that only 70% on average said yes to that question. Obviously, scientists from all disciplines participated in the survey and chemistry did better in Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com3tag:blogger.com,1999:blog-4387100009341358284.post-12679380175119490822017-02-20T09:59:00.001+01:002017-03-01T09:51:51.742+01:00Dry Column Vacuum Chromatography (DCVC) - The Movie!
I have on several occasions been asked to make a DCVC video tutorial and quite liked the idea of doing so. Thus, I have started my acting career as you can see in the video below. I think the video will be a useful guide for first time DCVCers. For more info you should consult this and this blog post on DCVC. Many thanks to the University of Copenhagen's Communication Department, in particular Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com23tag:blogger.com,1999:blog-4387100009341358284.post-30889734423594071412014-09-05T09:41:00.001+02:002014-09-05T09:42:54.845+02:00Total Recall - Synthetic organic chemistry is kinda slow and complicated!
To everyone's surprise I spent a day in the lab the other day doing some actual real life research. I forgot how hard, slow and complicated that stuff is. It would probably not be a bad idea for supervisors to leave the office and spend a day doing some lab work occasionally. I certainly appreciate what the guys are doing more after that ordeal. During my brief lab exposure I wasDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-66309878499745203702013-12-27T21:59:00.002+01:002013-12-27T21:59:30.913+01:00Curly Arrow - Established 18th October 2006
It really is becoming the rule rather than the exception that I forget Curly Arrow's birthday. Its been running for 7 years now and as always here are some stats on the year that has passed. As you can see the lack of new posts really isn't deterring people from using all the info posted here over the years (Although visitor numbers are in decline for the first time). Hopefully I can squeeze Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com4tag:blogger.com,1999:blog-4387100009341358284.post-57610019853844624542013-08-12T16:09:00.000+02:002013-08-12T16:09:41.348+02:00Free Ligands - The Calcilytic Agent NPS2143, a Calcium-Sensing Receptor Modulator
We recently synthesised a significant quantity of the calcilytic ligand NPS2143 for our research programme on G protein-coupled receptors. NPS2143 is a negative allosteric modulator of the human calcium-sensing receptor and as such an important pharmacological tool compound. Recently, we developed and published a synthesis of optically pure NPS2143 in Beilstein Journal of Organic ChemistryDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-49110795218056342362013-08-09T11:20:00.001+02:002013-08-09T11:20:30.294+02:00Faking it - Elemental Analysis!
Earlier this year I was refereeing a rather good paper and had I not taken the time to inspect the experimental section I would have accepted it with minor corrections. However, whoever wrote the experimental had clearly never run an elemental analysis before and was hopeless at making them up. The numbers were simply to good and although everything else looked great I had to Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-58198038607038772512013-01-07T09:28:00.001+01:002013-01-07T09:28:52.030+01:00Anti-GMO activist sees the light!
I picked this up at one of my favourite blogs (in the pipeline) and simply have to share it. A former fanatical anti-GMO campaigner read some scientific papers and realised his wrong doings. What a fantastic start to the New Year. It makes me think that there still may be hope for humanity when someone like Mark Lynas can come around and realise his mistakes and openly admit it. As a minimum Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com0tag:blogger.com,1999:blog-4387100009341358284.post-26840229932005477482012-12-11T23:07:00.001+01:002012-12-11T23:19:32.193+01:00Curly Arrow - Established 18th October 2006
So I missed my blog birthday again this year! As usual the stats for the past year at Curly Arrow follows below. Thanks to all the blog followers and everyone else who is using the blog. I wish I had more time to post stuff here but running my university research is very time consuming. When I finally get home I really need to do something that isn't chemistry to avoid going insane.
However,Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com1tag:blogger.com,1999:blog-4387100009341358284.post-588049673684317202012-12-11T22:02:00.001+01:002012-12-11T22:03:08.105+01:00Diazomethane and the Arndt-Eistert Homologation
For the past year we have been starting peptidomimetic chemistry up as a new research area in our group. Many chemists believe that peptide chemistry is easy and that peptide chemists aren't "real chemists". However, let me tell you from personal experience that there is absolutely nothing trivial about peptide chemistry. Even short sequences with normal alpha amino acids can be a nightmare to Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com5tag:blogger.com,1999:blog-4387100009341358284.post-2163709520360022102012-11-18T18:55:00.000+01:002012-11-18T19:51:08.138+01:00Diazotransfer - Synthesising Azides from Amines
In our group we work a lot with diazotransfer reagents and diazomethane so I thought it might be a good idea to share some of our knowledge. These reaction involve reagents that are very dangerous and azide products can also be explosive so you shouldn't do any of this chemistry without being 100% sure you know what you are doing. However, if experiments are performed thoughtfully and Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com6tag:blogger.com,1999:blog-4387100009341358284.post-91658064549791954132012-03-08T18:39:00.001+01:002012-03-08T18:39:52.545+01:00Total Synthsis?
We had our weekly journal club this morning. Interesting paper from a Korean group but maybe the ACS editorial office should wake up. D!Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com4tag:blogger.com,1999:blog-4387100009341358284.post-28875247801799845972011-12-27T16:25:00.001+01:002011-12-28T08:35:40.046+01:00Curly Arrow - Established 18th October 2006
Merry Christmas and Happy New Year! I Hope that everyone is getting some well-deserved time off. I used to do a yearly post on visitor stats around the blogs birthday but forgot this year!. Since it was the 5th birthday on 18th October 2011 I have decided to have a look back at how things developed in the past year.
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From 18th October 2010 to 18th October 2011:
Absolute
unique visitors:&Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com0tag:blogger.com,1999:blog-4387100009341358284.post-46354679983133661702011-11-21T22:23:00.010+01:002011-11-21T23:41:44.189+01:00Let's Talk About TLCs Part 5 - Iodine StainThe iodine stain is by far the easiest stain to prepare and use. The classic way is to simply have a chamber with some iodine crystals that you put your TLC plate into. The iodine vapours will react with many functional groups but is particularly good with unsaturated compounds (e.g. alkenes and alkynes) to give reddish brown spots (see TLC plate below). Another way to prepare the iodine stain isDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com9tag:blogger.com,1999:blog-4387100009341358284.post-59813708586413541052011-11-15T11:22:00.018+01:002011-11-16T23:38:59.351+01:00Reverse Phase Silica - Sort of!I'm sure that all the synthetic organic chemists will agree that column chromatography is something we simply couldn't live without. At our Department we use it in all its forms: Automated flash chromatography, Chromatotron, Prep. HPLC (Chiral and RP), Prep. TLC, old skool manual flash and DCVC columns etc. However, in spite of all this we all too frequently end up with stuff that is a major Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com25tag:blogger.com,1999:blog-4387100009341358284.post-55184907721718139502011-04-18T15:43:00.006+02:002011-04-18T16:00:22.217+02:00Triazoles in Peptidomimetic ChemistrySelf Promotion time! Our review on 1,2,3-Triazoles in Peptidomimetic Chemistry was just published in EuroJOC.Useful stuff if you are working in the peptidomimetic area. You can get it here or by emailing curlyarrow@gmail.com. D!Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2tag:blogger.com,1999:blog-4387100009341358284.post-91746884921497916632011-03-08T21:58:00.008+01:002011-03-08T22:38:45.794+01:00The Sand Bath - An Alternative to the Oil BathYes, I am still alive! I have been out of the lab for a loooong time so the inspiration hasn't been there. However, I am now finding myself in the lab again and it appears that I will get to stay there for a while. And today inspiration struck.Let's talk about oil baths. Good way to heat stuff up in a controlled way, BUT, what a bloody mess they are. The oil becomes disgusting after a while, theDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com14