Methanesulfonyl chloride groups

Direct halogenation of sucrose has also been achieved using a combination of DMF—methanesulfonyl chloride (88), sulfuryl chloride—pyridine (89), carbon tetrachloride—triphenylphosphine—pyridine (90), and thionyl chloride—pyridine—1,1,2-trichloroethane (91). Treatment of sucrose with carbon tetrachloride—triphenylphosphine—pyridine at 70°C for 2 h gave 6,6 -dichloro-6,6 -dideoxysucrose in 92% yield. The greater reactivity of the 6 and 6 primary hydroxyl groups has been associated with a bulky halogenating complex formed from triphenylphosphine dihaUde ((CgH )2P=CX2) and pyridine (90). 

Chemical Properties. Methanesulfonyl chloride (MSC) is a reactive chemical which allows iatroduction of the mesyl group, CH SO, into a... 

The mesylate group, introduced with methanesulfonyl chloride, can be cleaved with lithium aluminum hydride and dissolving metal reduction (Na, /-BuOH, HMPT, NH3, 64% yield). ... 

The azidohydrins obtained by azide ion opening of epoxides, except for those possessing a tertiary hydroxy group, can be readily converted to azido mesylates on treatment with pyridine/methanesulfonyl chloride. Reduction and subsequent aziridine formation results upon reaction with hydrazine/ Raney nickel, lithium aluminum hydride, or sodium borohydride/cobalt(II)... 

The oxygen atom at 21 is similarly an expendable group. Reaction of 241 (obtained from 185 by the usual procedure for introduction of the 9a-fluoro group) with methanesulfonyl chloride affords the 21 mesylate (242a). Replacement of the leaving group at 21 with iodine by means of potassium iodide in acetone followed by reduction of the halogen with zinc in acetic acid leads to fluorometholone (243). ... 

Activity is also retained when the hydroxyl group at the 21 position is replaced by chlorine. Reaction of corticoid 44 with methanesulfonyl chloride proceeds preferentially at the 21-hydroxyl (45) due to the hindered nature of the 11-alcohol. Replacement of the mesylate by means of lithium chloride in DMF affords clobetasol propionate (46) a similar sequence starting with the 17- butyrate ester 47, via mesylate 48, should give clobetasone butyrate, (49) [11]. 

Intermediate 10 must now be molded into a form suitable for coupling with the anion derived from dithiane 9. To this end, a che-moselective reduction of the benzyl ester grouping in 10 with excess sodium borohydride in methanol takes place smoothly and provides primary alcohol 14. Treatment of 14 with methanesulfonyl chloride and triethylamine affords a primary mesylate which is subsequently converted into iodide 15 with sodium iodide in acetone. Exposure of 15 to tert-butyldimethylsilyl chloride and triethylamine accomplishes protection of the /Mactam nitrogen and leads to the formation of 8. Starting from L-aspartic acid (12), the overall yield of 8 is approximately 50%, and it is noteworthy that this reaction sequence can be performed on a molar scale. 

Epiberberine and berberine were stereoselectively converted to fumaritrine (421) and its analog via 8,14-cycloberbines 216). The cycloberbine 432, derived from epiberberine (431) in the established way, was treated with p-toluenesulfonic acid in methanol and then with methyl iodide to give stereoselectively the cis-fused indenobenzazepine 433 in excellent yield (Scheme 86). Deoxygenation of the hydroxyl group in 433 was accomplished by treatment with methanesulfonyl chloride and subsequent reduction with sodium borohydride in dimethoxyethane to give (+ )-fumaritrine (421) (216). 

In addition, 85-90% yields of neryl chloride could be obtained from nerol, the geometrical isomer of geraniol. A modification4 of the above method has appeared which employs methanesulfonyl chloride and a mixture of lithium chloride, dimethylformamide, and collidine at 0° however, its applicability to compounds possessing sensitive groups was not demonstrated. 

The application of lithiumtrimethylsilyl acetate for the C-l elongation of aldonolactones has been examined (73). Although the reagent had been successfully used for the alkenation of lactone carbonyl groups (74), in the case of aldonolactones 10b or 25b only insignificant yields of the alkenes, but 30 - 40% of the lactols 49a or 50a, were obtained (73). However, these lactols, alternatively prepared in good yields by a Reformatsky-type reaction (53,54), were readily eliminated to the desired alkenes by simple treatment with methanesulfonyl chloride-triethylamine at 0°. Thus, from 49a or 50a separable E,Z mixtures (76a and 76b, or 77a and 77b, respectively) were obtained in good yields (73). 

Section 7.8). Other classes of derivatives are thus most conveniently prepared from the sulfonyl chloride. Reaction with an alcohol leads to formation of a sulfonate ester. Two common sulfonyl chloride reagents employed to make sulfonate esters from alcohols arep-toluenesulfonyl chloride, known as tosyl chloride, and methanesulfonyl chloride, known as mesyl chloride (see Section 6.1.4). Note the nomenclature tosyl and mesyl for these groups, which may be abbreviated to Ts and Ms respectively. 

The purpose of the first reaction with methanesulfonyl chloride (mesyl chloride) is to form a mesylate ester, a derivative with a better leaving group than hydroxide. Then, the Sn2 reaction can proceed more favourably. Esterification with mesyl chloride is mechanistically analogous to esterification with acetyl chloride. 

The reaction of methanesulfonyl chloride CH3SO2CI (to generate in situ the reactive sulfene CH2=S02) with chloral in triethylamine produced a /8-sultone bearing a trichloromethyl group at position Sultones... 

We have described (88TL4855) a simple synthesis of pyridin-2-ones by a two-step annulation of 2 with aliphatic acid chlorides (Scheme 27). The acylation of aminoazadienes 2 in pyridine furnished 4-amidoyl-l-azabutadienes 107 in high yields (85JOC802) lithium diisopropylamide-catalyzed aldol-type cyclization of 107 afforded pyridin-2-ones 108 in 83-94% yield. Extension of this reaction to methanesulfonyl chloride permitted preparation of open-chain derivatives 109 in 88-90% yield, which in turn cyclized in the presence of lithium diisopropylamide to 2//-l,2-thiazines 110 in 82-92% yield (89TL4705). Earlier work by the Komatsu-Ohshiro group showed that the reaction of simple 1-azadienes... 

SSRI activity is interestingly maintained even in the absence of one of the aromatic rings. Attaching the oxygen atom to an oxime leads to the antidepressant fluvoxamine. The requisite oxime (25-2) is obtained by reaction of the starting ketone (25-1) with hydroxylamine. Treatment of that intermediate with ethylene oxide adds the ether-linked side chain that will carry the amine. The hydroxyethyl product (25-3) is thus converted to its mesylate by means of methanesulfonyl chloride. This leaving group is then displaced by any one of several methods to afford the primary amine and thus fluvoxamine (25-4) [25]. 

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