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5-Aryl-3-(1,3-diphenylpyrazol-4-ylmethylene)-2(3H)-furanones (1a-c) were prepared by condensing 1,3-diphenylpyrazole-4-carboxaldehyde with 3-aroylpropionic acids in the presence of N,N-dimethyl(chlorosulfinyloxy)methaniminium chloride as a cyclodehydrating agent. The reactions of these furanones with anhydrous aluminium chloride in benzene, toluene and anisole led to the formation of 4,4-diaryl-1-(1,3-diphenylpyrazol-4-yl)buta-1,3-diene-2-carboxylic acids (6) as mixtures of two geometrical (E,E-and E,Z-) stereoisomers. The unfavoured intramolecular alkylation of 1a-c compared with other furanones is discussed using Hyper Chem Professional ( 7) AM 1 calculations.

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The reaction of some tertiary allylamines with dimethyl acetylenedicarboxylate in acetonitrile results in the formation of 1 : 1 adducts via [3,3] rearrangement of the ally1 group from nitrogen to carbon.Tertiary amines catalyse the nucleophilic addition of species HX to activated acetylenes.' In some other cases, adducts incorporating the amine moiety are obtained as the result of C-N bond cleavage. Winterfeldt has described a variety of such reactions involving the tertiary amino-ester (la) and -ketones (lb) and (2) with methyl propiolate to give p-aminocrotonates (3a) and (3b).' The formation of N-ethylpyrrole derivatives from tertiary amines (lb) and (lc) and acetylene esters involves loss of the second N-ethyl group in each case. Similarly triethylamine is reported to add to dimethyl acetylenedicarboxylate (DMAD) in the presence of a proton source to give compound (4a), for which the maleate configuration, not assigned at the time, is correct by comparison of spectral data with those of analogous corn pound^.^^^ N-Benzylaziridine catalyses the trimerisation of DMAD in aprotic solvents, but in t-butyl alcohol a 1: 1: 1 adduct (4c) is obtained through opening of the aziridine ring.' Meo2c&ozMe Et ,NCH2 R ( 1 ) a; R = CH,CO,Et H NR' R' 1 2 b; R = COPh ( 4 ) a; R = R = E t c; R = C02Me b; R ' , R 2 = (CH,), 1 C; R = CHZPh, R2= C H 2 C H 2 0 8~' d; R'= R2= Me 1 2 e; R , R =(CH212 1 2 1 2 ( C N C ti 2 c H 2)0 f ; R , R = CHzCH=CHCH2 9; R , R = (CH,),R1R2NCH=CHC02Me 1 2 1 ( 3 ) a; R = R = Et b; R , R 2 = (CH215 the same derivative (9b). Authentic samples of the by-products (4a) and (4b) were prepared from DMAD with diethylamine and piperidine, respectively, and similarly converted into the 2,4-dinitrophenylhydrazone derivative (9a). Catalytic hydrogenation of the adduct (7a) gave the corresponding propyl compound (8), which was characterised both as the 2,4-dinitrophenylhydrazone (9d), and by degradation to 2-oxohexanoic acid (Scheme 2). Me02C , C0,Me \ %+ , R1 R'R2NCH2CH=CHR3 -R37(&J,R2 ( 6 ) ( 5 ) a ; R 1 2 = R = E t , R 3 = H c ; R 1 = R 2 = Et, R 3 = Me I b; R', R2 = (CH2I5, R 3 = H Pd I H2 ( 7 a I -CH 1 3 ( 7 ) a ; R = R2= Et, R = H b; R', R 2 = (CH215, R 3 = H 1 c; R = RZ= Et, R3= Me Scheme 1. M e o z c~c o 2 N e -H~O + BuCOC02H Pr NEt, ( 8 1 Scheme 2.Me0,C COzMe Me02C \ /CO2Me Results and DiscussionWe have examined the addition of tertiary allylic amines to DMAD. Although no reaction occurs between allyldiethylamine (5a) and DMAD in dry ether, these compounds react readily in acetonitrile at room temperature to give the 1: 1 adduct (7a) together with smaller amounts of the aminomaleate ( 9 a; = (4a). The proportion of (4a) increased if water was added to the product (7a) even when thoroughly dry acetonitrile was used. the 1: 1 adduct (7b) and a smaller amount of (4b). The constitution of the adducts (7a) and (7b) was proved from their 'H n.m.r. and mass spectra and by hydrolysis in the presence of a x ; : //C -CH Me 2 , 4 -( 0 ,~ ),C~H,NHN ' R (10) system, but it still amounted to a small percentage of the m...

A cyanoacetohydrazide derivative underwent a series of reactions with different nucleophilic reagents, such as hydrazine hydrate, p-chlorobenzaldehyde and salicylaldehyde, to give the condensation products. In addition, an arylidene malononitrile was reacted with different nitrogen nucleophiles, such as hydrazine hydrate, thiocarbohydrazide and cyanoacetohydrazide, to afford the hydrazine, hydrazone and pyridin-2-one derivatives, respectively. Furthermore, a pyridin-2-one derivative was reacted with different carbon electrophiles, such as carbon disulfide, p-chlorobenzaldehyde and acetic anhydride. The antimicrobial activities of some of the compounds were examined.

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Ring closure of 2‐N‐benzylamino‐3‐aroylpropionic acids (3) with acetic anhydride afforded 3‐N‐benzylamino‐5‐aryl‐2(3H)‐furanones (4). The reaction of the furanones (4) with benzylamine in benzene was found to be time dependent. Thus refluxing the reaction mixture for 1 h only afforded the open‐chain amides (5a‐c). When the reaction was conducted for 3 h the 2(3H)‐pyrrolones (6) were obtained. Hydrazine hydrate affected ring opening of the furanones to give the hydrazides (5d‐f). Also, semicarbazide converted (4) into the corresponding semicarbazide derivatives (5g‐i). The hydrazides (5d‐f) were reacted with benzoyl chloride to give the corresponding diaroylhydrazines (5j‐l). The open‐chain derivatives (5) were converted into a variety of heterocycles: isothiazolones (7), dihydropyridazinones (8), 1,3,4‐oxadiazoles (9) and 1,2,4‐triazole derivatives (10) via cyclization reactions.