Methanesulfonate esters

Optically pure (S) (+) 2 butanol was converted to its methanesulfonate ester according to the reaction shown... 

C2oH fiClNO 149968-10-5) see Montelukast sodium [tx5-( )]-3-[2-(7-chloro-2-quinolinyl)ethenyl]-a-[2-[2-(l-methyl-l-[(tetrahydro-2//-pyran-2-yl)oxy]ethyl]phenyll-ethyl]benzenemethanol methanesulfonate (ester) (CjjHjgClNOjS 162489-71-6) see Montelukast sodium (5)-a-[3-[(E)-2-(7-chloro-2-quinolinyI)ethenyl]phenyl]-2-(l-hydroxy-l-methylethyl)benzenepropanol (C2i,H2xClN02) see Montelukast sodium (5)-a-[3-[( )-2-(7-chloro-2-quinolinyl)ethenyl]phenyl]-2-(l-hydroxy-l-methylethyl)benzenepropanol methanesulfonate... 

Methanesulfonate esters of secondary alcohols also give Friedel-Crafts products in the presence of Sc(03SCF3)341 or Cu(03SCF3)2.42... 

Methane refrigeration system, 10 617 Methanesulfonamide, 23 684 Methanesulfonate esters, 23 682 Methanesulfonic acid, 15 168 23 681-685 metal salts of, 23 684... 

N,7V -Diisopropyl)diamino-6-methanesulfonate ester 1,3,5-Triazine, see Prometrvn... 

ChemicaPPhysical. Mascolo et al. (1995) studied the reaction of prometryn (100 mM) with sodium hypochlorite (10 mM) at 25 °C and pH 7. Degradation followed the following pathway prometryn 2,4-(A/A -diisopropyl)diamino-6-methylsulfinyl-s-triazine 2,4-(N,W-disopropyl)-diamino-6-methylsulfonyl-1,3,5-triazine 2,4- (N, W-diisopropyl) diamino-6-methanesulfonate ester 5-triazine 2,4-(N,A -diisopropyl)diamino-6-hydroxy-s-triazine. 

Busulfan (Myleran) is a bifunctional methanesulfonic ester that forms intrastrand cross-linkages with DNA. The drug is well absorbed after oral administration and has a plasma half-life of less than 5 minutes. Metabolites and degradation products are excreted primarily in the urine. 

Alkylsulphonate Esters. Methanesulfonate esters such as busulfan (7.72) produce clinical remission in chronic myelogenous leukaemia. Busulfan acts through an Sfj2 nucleophilic displacement and presumably crosslinks DNA, since the methanesulfonate... 

In 1984 Gassman and Granrud, and Novak and co-workers, published their results on reactions of similar esters of hydroxamic acids. Gassman and Granrud showed that the rearrangement of the methanesulfonate esters 45a-g in CDCI3 (Scheme 23) occurred in a first-order fashion and that kobs correlated with with a slope,, of -9.2. Novak and co-workers showed that the pH-independent first-order rate constants for hydrolysis in 5 vol%... 

The CH3S02-0- group in methanesulfonate esters is a good leaving group, facilitating nucleophilic displacements. The utility of MSC for methanesulfonylation is well known in the agricultural, pharmaceutical, and specialty chemical industries. Methanesulfonyl chloride is a product of Elf Atochem North America (386—388). 

In parallel fashion, compound 267, made from 2,3 5,6-di-<9-isopropyl-idene-D-mannono-1,4-lactone by Reformatsky addition using ethyl bromo-acetate and zinc-silver graphite, undergoes ready elimination when converted to the methanesulfonic ester to give a separable mixture of the E- and Z-alkenes (268).251 Quite a different approach involves treatment of the 1-C-nitromannofuranosyl chloride, derived from the oxime of 2,3 5,6-di-O-isopropylidene-D-mannose, with the anion of diethyl malonate to give the disubstituted alkene 269.252... 

The (+)-l-allyl-5-ethyl-l,2,3,6-tetrahydro-pyridin-3-ol was converted into its methanesulfonate ester in the standard manner by treatment with methanesulfonic acid. 

Suitably substituted /3-lactams carrying methanesulfonate ester groups, for example, 445, underwent tandem elim-ination/intramolecular Diels-Alder reactions provided 4/5/6 fused tricyclic systems, for example, 446 <1999TL1015, 2000JOC3310>. 

Methanesulfonyl chloride may be a new reagent to you. In the presence of a base (usually triethy-lamine, EtjN) it reacts with alcohols to give methanesulfonate esters, but the mechanism differs from the mechanism with TsCl. The first step is an elimination of HC1 from the sulfonyl chloride (this can t happen with TsCl, because there are no available protons) to give a sulfene. The sulfene is highly electrophilic at sulfur, and will react with any alcohol (including tertiary alcohols, which react very slowly with TsCl). Here are the two mechanisms compared, formation of toluenesuifonates (tosylates) reagents ROH + TsCl + pyridine... 

Thin-layer chromatography is frequently employed for following the course of chemical reactions and for small-scale, preparative purposes. Often, it may be advantageous to employ a fluorescent adsorbent and to use a p-toluenesulfonic ester instead of the corresponding methanesulfonic ester, since p-toluenesulfonic esters can then be located by examination of a chromatoplate under ultraviolet light. 

Similar reactions of 2-methanesulfonic esters with sodiiun methoxide have been described by Fletcher and coworkers 1,3,5-tri-0-benzoyl-2-0-(methylsulfonyl)-a-D-ribose afforded methyl a-D-arabinopyranoside. From l,3,5-tri-0-benzoyl-2-0-(methylsul-fonyl)-/8-D-arabinose, a mixture of methyl /3-D-ribofuranoside and methyl /3-D-ribopyranoside was obtained, whereas only the latter glycoside was isolated when 2-0-(methylsulfonyl)-l,3,5-tri-0-(p-nitrobenzoyl)-)8-D-arabinose was the starting material. 

MERCAPTANS l-Acetyl-2-thiouiea. METHANESULFONATE ESTERS Meth-anesulfonyl chloride. 

The sulfur atom of naphthothiete 205 may be methylated with trimethyl-oxonium tetrafluoroborate to give the stable salt. 3-Phenylthiete 213 may be alkylated with trimethyl- or triethyloxonium tetrafluoroborate or the trifluoro-methanesulfonate esters The salts are unstable. Alkylation of 218b with methyl iodide gives a ring-opened product, the reaction being facilitated by electron donation from the iron atom. ... 

Photolysis of 3-thietanone involves both singlet and triplet excited states the initial products are sulfene and ketene, as determined by IR spectroscopy at liquid nitrogen temperatures in a pentane matrix.When the photolysis is done in methanol, isopropyl alcohol, or r-butyl alcohol, these intermediates are trapped as the acetate and methanesulfonate esters. In diphenylmethanol solvent, the bis-diphenylmethyl ether is formed by displacement of the alcohol on the sulfonate ester. Photolysis of tetramethyl-3-thietanone 1,1-dioxide gives dimethylketene. ... 

Methanesulfonate esters (mesylates).1 Mesylates can be prepared in 85-95 % yield by the reaction at 0-10° of an alcohol in methylene chloride (or cyclohexane or pentane) containing a 50% molar excess of triethylamine with a 10% excess of mesyl chloride, added over a period of 5-10 min. The reaction probably involves the sulfene CH 2 =SOz, formed by dehydrochlorination of mesyl chloride. Tertiary and neopentyl alcohols can be esterified by this procedure. Even reactive mesylates can be prepared if the temperature of the mesylate is kept at 0°. 

---