Arora, Anjali

Joshi, Susan

Nadir, UK

NOPR

Indian Journal of ChemiItryVol. 36B, February 1997, pp. 180-181Reaction of a-halosilanes with N-arylide-nearylsulfonamides- Attempted synthesisof N-arylsulfonylaziridinesUK Nadir", Anjali Arora & Susan JoshiDepartment of Chemistry, Indian Institute of Technology,New Delhi 110 016, IndiaReceived 9 January 1996; revised and accepted 24 July 1996Reaction of c-halosilanes with fluoride ions gener-ates carbanions I, through the attack of fluoride ionon the Si atom, and these are reported to transfermethylene to suitable double bondsl-3• Thus Kessar etal:4 have shown that 1 reacts with aldehydes to giveoxiranes and with a,~-wisaturated ketones and estersto yield the corresponding cyclopropanes (SchemeJ).This behaviour of the carbanions 1 parallelsthat of sulfur ylides"; sulfonium and sulfoxoniummethylides also transfer! a methylene to>C=C<, >C=O and to a lesset extent to> C = N -. We report herein the reaction of a-halo silane derived carbanions with N-arylidenear-ylsulfonamides as a possible route to aziridinesand communicate rather unexpected results.N-Arylsulfonylimines 2a-d6 were reacted withCsF ang halomethyltrimethylsilane in dry DMF.In each case a solid product was isolated which inIR spectrum showed a strong signal at 3260em - 1. The 1H NMR spectra of these productsshowed a broad triplet between b4.35 and 4.45-integrating for one proton which disappeared onD20 shake, and a singlet at b - 0.04 (9H) besidesaromatic protons at b7.4-8.0 integrating for ap-propriate number of protons. The l3C NMRNotej.,~/0"RHC--CHR'R=CzHs.X=8rR. H. X=Cl~CH-C-'RZIIoSchemel20-4a X-H.Y-Hb X-H.Y -Clc X-H.Y-CH,d XaOCH,.Y=HScheme IIspectra of the products exhibited a quartet at[)- 3.02, a triplet at 32.20 and aromatic carbonsbetween 127.38 and 132.49. On the basis of spec-tral data the products were assigned structure 3(Scheme II).Replacing chloromethyltrimethylsilane with bro-mo- or iodo-methyltrimethylsilane gave the sameproduct 3. When the source of fluoride ion waschanged from CsF to tetrabutylammonium fluo-ride, no change in the course of the reaction wasobserved (Table I). The only other product isolat-ed from the reaction mixture was the correspond-ing arylsulfonamide, derived probably from the,Table I-Results of the reaction of c-halosilanes with N-arylidenearylsulfonamides 1Reactant a-Halosi1ane Fluoride source Product Yield m.p.(%) ·C1. CICHzSiMe3 CsF 3. 71 51-531b C1CHzSiMe3 CsF 3b 71 96-981c ClCHzSiMe3 CsF 3c 70 62-641d ClCHzSiMe3 CsF 3c 69 521b BtCHzSiMe3 CsF 3b 65 96-971b ICHzSiMe3 CsF 3b 64 96-971. CICHzSiMe3 Bu4N+F- 3. 75 51-521b CICHzSiMe3 Bu4N+F- 3b 81 96-981d CICHzSiMe3 Bu4N+F- 3. 68 52hydrolysis of the unreacted Schiff base. In theabsence of CsF, no reaction took place.Experimental SectionGeneral method for the reaction of N-arylid-enearylsulfonamides 2 with o-halosilanes. Ce-sium fluoride (7.2 mmoles) in a flame dried evac-uated r.b. flask was dried by heating with a flame.The vacuum was released into an atmosphere ofN2 and halomethyltrimethylsilane (3.6 mmoles) indry DMF (10 mL) added to the flask. After stirr-ing for 10 min, the pertinent imine (3.6 m moles)in dry DMF (10 mL) was added and the stirringcontinued overnight. The reaction mixture was di-luted by adding] ice-cold .water (25 mL) and thewhole mixture extracted with ether (3 x 25 mL).NOTES 181The combined ethereal extracts were washed withwater (1 x 10 mL) and dried over anhydrous sodi-um sulfate. Removal of the solvent and crystalli-zation of the residue from benzene-pet. ether gavethe product.References1 Majetich G, Casares A, Champman D & Behnke M, J OrgChern, 51, 1986, 1745.2 Cooke F & Magnus P, Chern Cornrnun, 1977,513.3 Burford C, Cooke F, Ehlinger E & Magnus P, J Arn ChernSoc, 99,1977,4536.4 Kessar S V, Singh P & Venugopal D, Indian J Chern, 26B,1987,605.5 Trost B M & Melvin L S (Jr), Sulfur ylides, (AcademicPress, New York) 1975.6 Albrecht R, Krisze G & Malkar B, Chern Ber, 97, 1964,483.

Reaction of ɑ-halosilanes with N-arylide-nearylsulfonamides-Attempted synthesis of N-arylsulfonylaziridines

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Reaction of ɑ-halosilanes with N-arylide-nearylsulfonamides-Attempted synthesis of N-arylsulfonylaziridines

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