(Hive Addict)
09-24-03 02:55
No 460643
(Rated as: good read)
Toluenesulfonylbromide, steppingstone to M/Ethyltosylate, relatively gentle alkylating agents. Ethyltosylate can also be used to make nitroethane[1] but there's other fun things you can do with tosylbromide,too. See some related buzz at Post 417550 (Antoncho: "Methyl tosylate: _finally_ , OTC!!!", Novel Discourse). What I want to discuss here is an alternate synthesis pathway: MePhSO3Na + Ph3P*Br2. That can be found in [2], which should be easily retrievable using a test account as described in Post 363228 (Rhodium: "Free Online Chemistry & Medicinal Journals", Novel Discourse), I wasn't able to establish a connection to the Thieme server for the last ~20h so I'd be most grateful if someone could post here what the article says.
Concerning the Ph3P*Br2 [3]:
To an ice-water bath cooled solution of PPh3 (457mg, 1.74mmol) in 4ml of CH2Cl2
under argon was added Br2 (0.87 mL, 1.7mmol). after an additional 5min ... they
add a diol here ... what's important is that after 5min the PPh3 + Br2 --> Ph3P*Br2
rxn is complete enough to proceed. Well, I pretty much hate them for doing it so
microscale, but you see that it is mainly cool, add, stir, wait. Why do they use Ar ?
[1]Rodionow; BSCFAS; Bull.Soc.Chim.Fr.; <4> 39; 1926; 318; BSCFAS; Bull.Soc.Chim.Fr.; <4> 45; 1929; 119.
[2]Kataoka, Tadashi; Iwama, Tetsuo; Setta, Tomofumi; Takagi, Atsuko; SYNTBF; Synthesis; EN; 4; 1998; 423-426
[3]McPhee, Mark M.; Kerwin, Sean M.; BMECEP; Bioorg.Med.Chem.; EN; 9; 11; 2001; 2809 - 2818
see also:
Roy, Aroop K.; JACSAT; J.Amer.Chem.Soc.; EN; 115; 7; 1993; 2598-2603 and
Freydank, Anke C.; Humphrey, Mark G.; Friedrich, Reiner W.; Luther-Davies, Barry; TETRAB; Tetrahedron; EN; 58; 7; 2002; 1425 - 1432
--psyloxy--
(Chief Bee)
09-24-03 03:12
No 460646
(Rated as: good read)
Preparation of Sulfonamides from Sodium Sulfonates: Ph3P·Br2 and Ph3P·Cl2 as a Mild Halogenating Reagent for Sulfonyl Bromides and Sulfonyl Chlorides
Tadashi Kataoka, Tetsuo Iwama, Tomofumi Setta, Atsuko Takagi
Synthesis (4), 423-426 (1998) (../rhodium/pdf /nasulfonate2
Abstract
Arene- and alkanesulfonamides were prepared by treatment of the corresponding sodium sulfonates with triphenylphosphine dibromide or dichloride followed by amines in the presence of triethylamine via sulfonyl halides. Reactions of sodium aminosulfonates gave cyclized products. Amidation of p-toluenesulfonic acid with triphenylphosphine dichloride was also examined to give N-benzyl-p-toluenesulfonamide. Methyl p-toluenesulfonate was obtained by esterification of sodium p-toluenesulfonate via ptoluenesulfonyl chloride.
(Active Asperger Archivist)
12-13-03 06:58
No 476567
Could somebody get a translated (to english) version of reference one from Psyloxy's post?
Post 460643 (psyloxy: "tosylbromide from sodium tosylate / Ph3P*Br2", Chemistry Discourse)
Rodionow; BSCFAS; Bull.Soc.Chim.Fr.; <4> 39; 1926; 318; BSCFAS; Bull.Soc.Chim.Fr.; <4> 45; 1929; 119.
Thanks
Act quickly or not at all.