620 J.C.S. Perkin IHeterocycles from Ylides. Part 1V.l Reactivity of 4-Arylmethylene-Aa-pyrazolin-5-ones with Stabilized Sulphur YIidesBy Piero Dalla Croce," lstituto di Chimica lndustriale dell'UniversitA di Milano, C.N.R. Centro di Studio sullaDonato Pocar, lstituto di Chimica Organica della FacoltA di Farmacia dell'UniversitA di Milano, Viale AbruzziSintesi e Stereochimica di Speciali Sisterni Organici, Via Golgi 19, 201 33 Milano, ftaly42, 201 31 Milano, Italy4-Arylmethylene-1 -phenyl-A2-pyrazolin-5-ones react with carbonyl-stabilized sulphur ylides yielding spiro-[cyclopropane-1 ,4'-A2'-pyrazolin] -5'-ones, identified from spectroscopic data and chemical behaviour.SULPHUR ylides have found a wide variety of applications tives t from carbonyl-stabilized sulphonium ylides andin organic synthesis.293 We report the preparation of 4-arylmethylene-A2-pyrazolin-5-ones.spiro[cyclopropane-1 ,4'-A2'-pyrazolin]-5'-one deriva- The reaction of dimethylsulphonium phenacylide (1)with several (2) -4-arylmet hylene-A2-pyrazolin-5-ones (2)C.R. Johnson and C. Schroeck, J . Amer. Clzem. Soc., 1973,95, 7417.H. Wamhoff and F. Korte, Chenz. Bep., 1966, 99, 2962.7 Some simple derivatives have been reported pre~iously.~Part 111, P. Dalla Croce and D. Pocar, preceding paper.2 (a) C. R. Johnson, Accounts Chem. Res., 1973, 6, 344; (b)B. M. Trast, ibid., 1974,7, 851976 621afforded the spirocyclopropane derivatives (3a-4.Elemental analysis and i.r. data (characteristic cyclo-propane bands at 1 015-1 020 cm-l and pyrazolinoneC=O stretching6 at 1680 cm-l) confirmed the productstructures.The n.m.r. spectra showed an AB splittingpattern for the cyclopropane hydrogen atoms, allowingus to assign to the HaHB system the cis-configuration+ -Me2S-CHIPh-CO( 1 1H1The structure of the spiro [cycIopropanepyrazolin]oneswas supported by the following chemical transformation,Treatment of compound (3b) with potassium t-butoxidein dimethyl sulphoxide promoted abstraction of the 3-proton followed by cleavage of the cyclopropane 1,2-bond. This led to 4-(a-benzylidenephenacyl)-lJ3-di-phenyl-A2-pyrazolin-5-one (4), which by reaction withRC-C 6 2 P h( 3 )6bH A HE Jn.~lHz X M.p. (“C) Yield (%)H 131-132 85 4.05 4.26 9.0H 175-176 b 80 4.17 4.62 8.9169-160 0 80 3.97 4.18 9.0 %k 147-148 * 76 4.12 4.30 9.1a From ethanol.* From ethyl acetate.SCHEME 1on the basis of the coupling constants ( J ca. 9 Hz). Theproducts (3a-d) could therefore have structure (A) or(B) -Ph .H coR H \ R P h iMolecular models of compounds (3a and b) indicatethat in structure (B) there exists a considerable stericinteraction between the pyrazoline 3-substituent and thecyclopropane 2- and 3-substituents, whereas structure(A) appears markedly less crowded.It is known * that 4-arylmethylene-A2-pyrazolin-5-ones show the mesomerism illustrated in Scheme 2.Accordingly, products from 1,2- or 1,4-cycloaddition+CH-C6HLX - 4 , /C H-C,H,X - 4 /-y \ N O / \ - [j, N 0 - ’ c+I 1SCHEME 2might be expected.However, the reaction gave only1,2-~ycloaddition products. This behaviour is similarto that of stabilized sulphur ylides with aP-unsaturatedcarbonyl compounds, affording, via Michael-type addi-tion , cyclopropane derivative^.^J. D. Graham and M. T. Rogers, J. Amer. Chem. SOC., 1962,R. H. Wiley and P. Wiley, ‘ Pyrazolones and Derivatives,’84, 2149.Interscience, New York, 1964.hydrazine in ethanol afforded 1 ,3-diphenyl-A2-pyrazolin-&one (5) and 3,5-diphenylpyrazole (6).CHPh PhC- CH - C’13b) 11 I ‘COPhN\ A* NPh1 4 )PhC- C H PhC- CH2I1 II + If IN, ,CPh N\N NH Ph161 (51SCHEME 3The mildness and simplicity of our reaction contributeto the general utility of carbonyl-stabilized sulphurylides in this regiospecific and stereoselective route tospiro[cyclopropanepyrazolin]ones.EXPERIMENTALN.m.r. spectra were measured with a Varian A-60spectrometer (solvent C,D, ; Me,Si internal standard). 1.r.spectra were recorded with a Perkin-Elmer 137 Infracordspectrophotometer for ca.2 % solutions in chloroform.H. Booth, Progr. NMR Spectroscopy, 1969, 5, 167; L. M.Jackman and S. Sternhell, ‘Applications of Nuclear MagneticResonance Spectroscopy in Organic Chemistry,’ Pergamon,Oxford, 1969. * G. Cellerino, G. Desimoni, P. P. Righetti, and G. Tacconi,Gazzetta, 1973, 103, 1947.A. W. Johnson and R. T. Amel, J. Org. Chem., 1969. 84.1240622 J.C.S. Perkin IElemental analyses for new compounds are available asSupplementary Publication No. SUP 21652 (2 pp.).*4-A rylmethylene- 1 -phenyl- Az-~yrazolin-5-ones,- Thesewere prepared by reported methods lo from l-phenyl-3-methyl- or 1, 3-diphenyl-A2-pyrazolin-5-ones and theappropriate aldehyde.Preparation of Spiro[cyclopropanepyrazolin3ones (3a-d) :General Procedure.--A solution of dimethylsulphoniumphenacylide 9 (1) (0.01 mol) in 1,2-dimethoxyethane (25 ml)was added to a stirred suspension, cooled to -20 OC, of the4-arylmethylene- 1-phenyl-A2-pyrszolin-5-one (0.01 mol) inthe same solvent (50 ml). The mixture was stirred for 2 hand then the solvent was evaporated off and the residuewas crystallized.4- (a-Benzylidenephenacyl) - 1, 3-diphenyl-A2-pyrazo lin-5-on e(4).-A mixture of compound (3b) ( 1 g) and potassium t-butoxide (0.295 g) in dimethyl sulphoxide (30 ml) was keptovernight a t room temperature.The solvent was evapor-ated off under vacuum and the residue taken up with water* For details of Supplementary Publications see Notice toAuthors No. 7, J.C.S. Perkin I , 1975, Index issue.(26 ml) and ether (60 ml). The aqueous layer was acidifiedwith acetic acid and the precipitate filtered off. Theproduct was purified from ethanol; yield 0.75 g (75%);m.p. 130".Reaction of the Pyruzolinone (4) with Hydrazine.-Asolution of compound (4) (1 g) in ethanol (50 ml) was treatedwith hydrazine hydrate (0.14 g) and refluxed for 4 h.Evaporation left an oily residue which was dissolved inether. Extraction with aqueous 10% sodium hydroxide(20 ml) followed by acidification with hydrochloric acid( 2~ ; 20 ml) afforded 1, 3-diphenyl-A2-pyrazolin-5-one (5)(0.37 g, 70%), m.p. 134". From the ether layer by con-ventional work-up, 3,5-diphenylpyrazole (6) was isolated(0.32 g, 65%); m.p. 198". Both compounds (5) and (6)showed no m.p. depression in admixture with authenticsamples.We thank the Consiglio Nazionale delle Ricerche, Rome,for financial support.[5/1425 Received, 18th July, 19761lo G. Desimoni, A. Gamba, P. P. Righetti, and G. Tacconi,Guzzetla, 1972,102,491
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