Methanesulfonyl group

MSC undergoes reactions with alcohols, amines, active methylene compounds (in the presence of bases), and aromatic hydrocarbons (in the presence of Friedel-Crafts catalysts) to replace, generally, a hydrogen atom by a methanesulfonyl group (382—401). 

The 9-methylsulfonyl-pyrimido[l,6-tf]pyrimidin-6,8-dione 210 was obtained during attempted mesylation of the 6-[(3-hydroxypropyl)amino]uracil 209 (Equation 25). The methanesulfonyl group of 209 was removed by reduction with Raney Ni to yield 68 <1999JHC453>. 

Methanesulfonyl group is called a mesyl group and /7-toluenesulfonyl group is... 

Use of ferrocenylmonophosphine (fU-(A)-PPFA 5a for the same reaction improved the enantioselectivity.24,25,26 Here, the hydrosilylation product was oxidized into ( y)-l-phenylethanol 3 with 52% ee (entry 3). The ferrocenylmonophosphine 6 supported on Merrifield polystyrene resin has been also used for the hydrosilylation of styrene, though the enantioselectivity was lower (15% ee) (entry 4).27 Several chiral (/ -/V-sulfonylaminoalkyl)phosphines 7 were prepared from (A)-valinol and used for the asymmetric hydrosilylation of styrene.28 For styrene, phosphine 7a which contains methanesulfonyl group was most effective giving (asymmetric hydrosilylation (entries 6-9).29,29a... 

The direct nucleophilic displacement of a thione at position 7 has been reported (Scheme 13), together with the further conversion of the resulting hydrazine to an azide or to a triazole <1998FA113>. Similarly, 7-amination has been carried out by displacement of methanesulfinyl and methanesulfonyl groups <2006BMCL4257>. 

With heteroaromatic amines as diazo component, e.g., the red dye 25, which is an example for the use of the methanesulfonyl group as an acceptor in azo dyes. 

The search for endothelin antagonists as potential compounds for treating cardiovascular disease was noted in Chapter 5 (see atrasentan). A composed with a considerably simpler structure incorporates a pyrimidine ring in the side chain. Condensation of benzophenone (94) with ethyl chloro-acetate and sodium methoxide initially proceeds to addition of the enolate from the acetate to the benzophenone carbonyl. The aUcoxide anion on the first-formed quaternary carbon then displaces chlorine on the acetate to leave behind the oxirane in the observed product (95). Methanolysis of the epoxide in the product in the presence of boron triflor-ide leads to the ether-alcohol (96). Reaction of this with the pyrimidine (97) in the presence of base leads to displacement of the methanesulfonyl group by the aUcoxide from 96. Saponification of the ester group in that product gives the corresponding acid, ambrisentan (98). " ... 

Equation 1 shows the replacement of dltrlfyl Imlde by a bromide Ion. By comparison. Equation 2 shows the replacement of trlfluoro-methanesulfonyl group on a nitrogen by an alkoxlde and Equation 3 demonstrates that a substitution reaction can take place on a sulfonyl group by a carboxylate to yield the trlfluoromethane-sulfonyl ester. 

A key step in a synthesis of ketorolac, an analgesic and anti-inflammatory agent, involves an intramolecular nucleophilic displacement of a methanesulfonyl group activated by a 5-ketone. ... 

Recently, Miranda and coworkers reported that tin hydride-mediated radical carbonylation can be applied to include the synthesis of ketones fused with heterocyclic rings, such as pyrroles and indoles. In the example given in run 10, an acyl radical attack at aromatic carbon and in situ oxidation leads to an indole-fused cyclopentanone in good yield [39]. On the other hand, an example shown in run 11 makes use of a methanesulfonyl group as a leaving radical [40]. When a related substrate which does not contain a sulfonyl substituent was used, a simple radical formylation took place. 

A methanesulfonyl group (as methanesulfinate) is also a good leaving group in all of the diazines," generally better than chloro, sometimes considerably so, for example 3-methanesulfonylpyridazine reacts 90 times faster with methoxide than does 3-chloropyridazine. Sulfmates can be used to catalyse displacements of chlorine via the intermediacy of the sulfone." ... 

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