ORGLIST: Reply: Regarding molecular seive

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From: shailesh patel m (shailptl$##$rediffmail.com)
Date: Thu Nov 27 2008 - 13:30:30 EST


Dear All, If reaction using molecular seive has to left for stirring for longer period of time using the magnetic stirring, it is bound to crush during this period. May I request any additional comments to avoid this. Do molecular seive in form of bead or in rod shape will make any difference ?(as far as drying is concern, theoretically it should not). Other day I was tinkering with the idea of using sodium sulphate as drying agent in the reaction. Is that too funny? On Thu, 27 Nov 2008 everybody-request$##$orglist.net wrote : >Send Everybody mailing list submissions to > everybody$##$orglist.net > >To subscribe or unsubscribe via the World Wide Web, visit > http://two.pairlist.net/mailman/listinfo/everybody >or, via email, send a message with subject or body 'help' to > everybody-request$##$orglist.net > >You can reach the person managing the list at > everybody-owner$##$orglist.net > >When replying, please edit your Subject line so it is more specific >than "Re: Contents of Everybody digest..." > > >Today's Topics: > > 1. Re: Molecular Sieve (Ilya Avrutov) > 2. Re: Molecular Sieve (James Giammarco) > 3. Re: molecular sieves (Alexey Gromov) > 4. Unstable product of iodolactonization (Suraya Zulkepli) > 5. brine/water washing (Ohad Ilovich) > > >---------------------------------------------------------------------- > >Message: 1 >Date: Wed, 26 Nov 2008 08:45:49 -0500 > From: "Ilya Avrutov" <IAvrutov$##$dalton.com> >Subject: Re: ORGLIST: Molecular Sieve >To: "mohd zulkefeli" <moha03jp$##$yahoo.co.jp>, <everybody$##$orglist.net> >Message-ID: > <3C4E01DBE4138446A742AC296B57F30D01200452$##$dalton-es.dalton.dcl> >Content-Type: text/plain; charset="us-ascii" > >Hello Mohd, > >By no means you need to crush the sieves: they will loose their potency >completely. For anhydrous conditions you are supposed the sieves 3A or >4A. But be sure they will not be crushed during stirring. > >Best, >Ilya Avrutov > >Ilya Avrutov, PhD >Process Development Team Leader >Dalton Pharma Services >349 Wildcat Rd., Toronto, ON >M3J 2S3 Canada > >________________________________ > > From: everybody-bounces$##$orglist.net >[mailto:everybody-bounces$##$orglist.net] On Behalf Of mohd zulkefeli >Sent: Wednesday, November 26, 2008 2:46 AM >To: everybody$##$orglist.net >Subject: ORGLIST: Molecular Sieve > > >Dear Colleagues, > >I would like to seek opinion on using molecular sieve during anhydrous >reaction. Which one is more effective, using the molecular sieve in its >original shape or crush it to the powder shape? > >Thank you very much. > >M. Zulkefeli > >________________________________ > >Power up the Internet with Yahoo! Toolbar. ><http://pr.mail.yahoo.co.jp/toolbar/> > >-------------- next part -------------- >An HTML attachment was scrubbed... >URL: <http://two.pairlist.net/pipermail/everybody/attachments/20081126/85f02939/attachment-0001.htm> > >------------------------------ > >Message: 2 >Date: Wed, 26 Nov 2008 12:30:05 -0500 > From: "James Giammarco" <drexchem2008$##$gmail.com> >Subject: Re: ORGLIST: Molecular Sieve >To: everybody$##$orglist.net >Message-ID: > <8fe66bc50811260930w4365dd08kd9f3dd3adc7d83a3$##$mail.gmail.com> >Content-Type: text/plain; charset="iso-8859-1" > >Hi Mohd Zulkefeli, > In my experience, I find that using the sieves whole is just as good >as using them crushed and you will have an easier time to filter them if >they are whole. In any case, you have to remember to activate them by which >I mean heat them in a ceramic dish on a hot plate or as I did over a Bunsen >burner for a *short* period of time to remove any water. When you hold >about 5-6 in your hand and add a few drops of water, they should get HOT. >If they don't, they are already filled with water. Hope that helps some. > >Sincerely >James Giammarco > >On Wed, Nov 26, 2008 at 12:00 PM, <everybody-request$##$orglist.net> wrote: > > > Send Everybody mailing list submissions to > > everybody$##$orglist.net > > > > To subscribe or unsubscribe via the World Wide Web, visit > > http://two.pairlist.net/mailman/listinfo/everybody > > or, via email, send a message with subject or body 'help' to > > everybody-request$##$orglist.net > > > > You can reach the person managing the list at > > everybody-owner$##$orglist.net > > > > When replying, please edit your Subject line so it is more specific > > than "Re: Contents of Everybody digest..." > > > > > > Today's Topics: > > > > 1. Molecular Sieve (mohd zulkefeli) > > > > > > ---------------------------------------------------------------------- > > > > Message: 1 > > Date: Wed, 26 Nov 2008 16:45:33 +0900 (JST) > > From: mohd zulkefeli <moha03jp$##$yahoo.co.jp> > > Subject: ORGLIST: Molecular Sieve > > To: everybody$##$orglist.net > > Message-ID: <20081126074533.92281.qmail$##$web3211.mail.kcd.yahoo.co.jp> > > Content-Type: text/plain; charset="iso-2022-jp" > > > > Dear Colleagues, > > > > I would like to seek opinion on using molecular sieve during anhydrous > > reaction. Which one is more effective, using the molecular sieve in its > > original shape or crush it to the powder shape? > > > > Thank you very much. > > > > M. Zulkefeli > > > > > > > > --------------------------------- > > Power up the Internet with Yahoo! Toolbar. > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > > http://two.pairlist.net/pipermail/everybody/attachments/20081126/b5df474c/attachment.htm > > > > > > > ------------------------------ > > > > _______________________________________________ > > ORGLIST - Organic Chemistry Mailing List > > Website / Archive / FAQ: http://www.orglist.net > > To post a message (TO EVERYBODY) send to everybody$##$orglist.net > > To unsubscribe, send to everybody-request$##$orglist.net the message: > > unsubscribe your_orglist_password your_address > > > > End of Everybody Digest, Vol 53, Issue 4 > > **************************************** > > > > > >-- >Sincerely, > >James M Giammarco >MS&E Graduate Student >Clemson University >Office: Sirrine 060 >Office #: 864-656-0888 >jmgiamm$##$clemson.edu >-------------- next part -------------- >An HTML attachment was scrubbed... >URL: <http://two.pairlist.net/pipermail/everybody/attachments/20081126/86c4357d/attachment-0001.html> > >------------------------------ > >Message: 3 >Date: Wed, 26 Nov 2008 18:56:42 +0100 > From: "Alexey Gromov" <alexey.gromov$##$univie.ac.at> >Subject: Re: ORGLIST: molecular sieves >To: everybody$##$orglist.net >Message-ID: > <e81f08bd0811260956i161ba2bevbcd8de04fb74c356$##$mail.gmail.com> >Content-Type: text/plain; charset=ISO-8859-1 > >I think there is no answer on this question. According to one >investigation, for example, MeOH drying over powdered MS 3A gives much >worse results than over beads. At the same time, for EtOH and t-BuOH >using powder gives substantially superior results: >http://chemknowhow.com/forum/viewtopic.php?p=562#562 >But in general, what i have seen people use equally often powder (one >has to crash beads first and then activate the powder, not vise >versa!) and beads. >I personally prefer powder, but have never studied the difference for >my reactions. > >About some issues with mol. sieves see here: >http://chemknowhow.com/forum/viewtopic.php?t=124 > >Best regards, >Alexexy > > >------------------------------ > >Message: 4 >Date: Thu, 27 Nov 2008 00:25:13 -0800 (PST) > From: Suraya Zulkepli <kinrara_16$##$yahoo.com> >Subject: ORGLIST: Unstable product of iodolactonization >To: everybody$##$orglist.net >Cc: ratna_rimba$##$yahoo.com, nicque <buzwifme7$##$yahoo.com> >Message-ID: <991350.58940.qm$##$web53909.mail.re2.yahoo.com> >Content-Type: text/plain; charset="us-ascii" > >hello all.. > >I would like to ask why the iodolactonization process ALWAYS got unstable product compared to bromolactonization is more stable product to form it? >Is it bromine used more better than iodine ? > >I hope anyone can answers it..THANK YOU..:) > >Best regards, > >SURAYA > > > > >-------------- next part -------------- >An HTML attachment was scrubbed... >URL: <http://two.pairlist.net/pipermail/everybody/attachments/20081127/f7fee29f/attachment.htm> > >------------------------------ > >Message: 5 >Date: Thu, 27 Nov 2008 13:09:41 +0200 > From: "Ohad Ilovich" <ilovicho$##$gmail.com> >Subject: ORGLIST: brine/water washing >To: everybody$##$orglist.net >Message-ID: > <2a10291c0811270309n431de058u2cab1d5c7f40c991$##$mail.gmail.com> >Content-Type: text/plain; charset="iso-8859-1" > >Dear all, >I have a rather strange question. I've seen in a couple of articles where >someone extracted his compound in some organic solvent and than washed the >organic phase in both brine and water. >As i understand it brine is used when the organic solvent is miscible with >water and the salting out effect of the brine inhibits the compound >dissolved in the organic phase from passing to the brine. water is used >pretty much of all other solvents. >The only idea why brine AND water will be used is to maybe get rid of any >NaCl leftover which may have passed to the organic phase. >Am i mistaken or is this double washing just a waste of time? > >-- >Ohad Ilovich, M.Sc, B.Pharm >Cyclotron/Radiochemistry Unit >Nuclear Medicine Department >Hadassah/Hebrew University Hospital >Jerusalem 91120, Israel >Fax : 972 2 6412033 >Tel: 972 2 6777197 >-------------- next part -------------- >An HTML attachment was scrubbed... >URL: <http://two.pairlist.net/pipermail/everybody/attachments/20081127/b99539b3/attachment-0001.html> > >------------------------------ > >_______________________________________________ >ORGLIST - Organic Chemistry Mailing List >Website / Archive / FAQ: http://www.orglist.net >To post a message (TO EVERYBODY) send to everybody$##$orglist.net >To unsubscribe, send to everybody-request$##$orglist..net the message: unsubscribe your_orglist_password your_address > >End of Everybody Digest, Vol 53, Issue 5 >**************************************** Shailesh Patel(Ph.D. scholar) Department of Pharmaceutical Chemistry, L.M.College of Pharmacy, Navrangpura Ahmedabad 380009 Gujarat, INDIA Mobile : 9824443327


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