摘要:
Org. 1923 Reactions with Asymmetric Diarylethylenes and Diarylethanes. Part X I W Addition of Xanthenyl Chloride to the Ethylenes By Wadie Tadros," Alfy Badie Sakla, Munir Gindy, and Nadia Fouad, Chemistry Department, Faculty of Science, Cairo University, Egypt Xanthenyl chloride adds readily to asymmetric diarylethylenes to give after dehydrochlorination, 1 ,I -bis- (p-sub- stituted pheny1)-2- (xanthen-9-y1)ethylenes. The nature of the para-substituent in the olefinic products has an influence on their reaction with bromine. In the presence of p-alkoxy-groups 1 ,I -bis-(p-alkoxyphenyl) -2-bromo- 2-(xanthen-9-yl)ethylenes are obtained as main products ; small quantities of xanthenyl tribromide, 1 ,I -diaryl- 2-bromoethylenes, and xanthen are also isolated. The latter three compounds are the main products when the para-substituents are bromine, chlorine, or hydrogen.The structures of the 1,l -bis-(p-alkoxyphenyl)-2-bromo-2-(xanthen-9-yl)ethylenes were confirmed by (a) ozonolysis and (b) transformation with alcoholic potassium hydroxide into the corresponding allenes [I ,I -bis- (p-alkoxyphenyl)-2- (xanthen-9-ylidene) ethylenes]. DIPHENYLMETHYL BROMIDE or chloride adds to asym- metric diarylethylenes (11) to give the corresponding tetra-arylpropenes.2 We now show that xanthenyl chloride ( I ; X = Cl) adds also to asymmetric diaryl- ethylenes (11; R = H, MeO, EtO, PriO, Me, Br, or Cl) to give products which, without being isolated, are con- verted by ethanolic potassium hydroxide into 1,l-bis- ($-substituted pheny1)-2- (xanthen-9-yl) ethylenes (I11 ; R = H, MeO, EtO, PriO, Me, Br, or Cl).Better yields were obtained when the diarylethylene (11) was added to a solution of an equimolecular quantity of xanthenol in dry ether saturated with hydrogen chloride. YX + H2C:C(C6H4R-$)2 + [YCH2*CX(C&&R-$)2] Y = Xanthen-9-yl YCH:C(C,H,R-$), (111) This method represents an elegant synthesis for this type of compound. The first member of the series, l,l-diphenyl-2-(xanthen-9-yl)ethylene (I11 ; R = H) has been previously prepared by two methods: (i) reduction of 2-(9-hydroxyxanthen-9-y1)-1 ,l-diphenylethylene obtained from diphenylvinylmagnesium bromide and xanthone, and (ii) dehydration of 1-hydroxy-1,l- diphenyl-2- (xant hen-9-yl) et hane obtained from phenyl- magnesium bromide and ethyl xanthenylacetate. A common U.V.absorption band at 256 nm. (log E 44-45) was shown by all the ethylenes (111; R = H, MeO, EtO, PriO, Me, Br, or Cl). Another band at 251 nm. was shown by the ethylenes (111; R = H or Me) (log E 4.4 and 4.3, respectively). Two other bands, at 264 and 244 nm. were shown by the ethylenes (111; R = MeO, EtO, PriO, Br, or Cl)(log E 4-6, 4.4, and 4.5, respectively). The nature of the $am-substituent in the ethylenes (111) has an influence on their reaction with bromine. In the presence of $-alkoxy-groups (MeO, EtO, or PriO), 1 A. B. Sakla, W. Tadros, and M. K. Khalil, J . Chem. SOC. W. Tadros, A. B. Sakla, and A. A. A. Helmy, J . Chem. SOG., 3 K. Ziegler, G. Bremer, F. Thiel, and F. Thielman, Annalen, (C), 1970, 409. 1961, 2687. 1923, 434, 34.which exert a weak -I and a strong +M di~placement,~ bromine adds readily to give the corresponding 1 ,l-bis-(p- alkoxyphenyl)-2-bromo-2-(xanthen-9-yl)ethylenes (IV) as the main products. Small quantities of xanthenyl tri- bromide (V), 1 ,l-diaryl-2-bromoethylene (VI ; R = MeO, EtO, or PriO), and xanthen can also be isolated. However, when R is C1, Br, or H, compounds (V) and (VI) and xanthen are the main products. Ziegler and his co-workers3 have reported that treatment of 1,l- diphenyl-2-(xanthen-9-yl)ethylene with excess of bro- mine gives compound (V) and xanthen together with 1,2,2-tribromo-1, l-diphenylethane. The latter com- pound was apparently formed by bromination of the 2-bromo-1,l-diphenylethylene (VI ; R = H) which we obtained. The formation of xanthen may be attributed to the reactivity of the xanthenyl halides ( I ; X = Br) and (V) when the products are worked up with hydroxy- lic solvent^.^^^ The formation of compounds (V) and (VI) in the presence of P-alkoxy-substituents could involve the addition of bromine to the olefin (111; R = MeO, EtO, or PriO) followed by dehydrobromin- ation to give the bromo-compound (IV), with concurrent addition of liberated hydrogen bromide to the starting material (111) to give compound (VII).This could react with bromine to yield xanthenyl bromide (I) [which would react with excess of bromine to give the tribromide (V)] and 1, l-bis- ($-alkoxyphenyl)-l,2-di- bromoethane (VIII). Compound (VIII) could then lose hydrogen bromide to give l,l-bis-(P-alkoxyphenyl)-2- bromoethylene (VI; R = MeO, EtO, or PriO). The following observations support this mechanism.(i) When bromine is added to the xanthenylethylene (111; R = MeO, EtO, or PriO) in chloroform saturated with hydrogen bromide , little of the bromo-compound (IV) can be isolated; instead 1,1,4,4-tetrakis-(p-alkoxy- phenyl)buta-l,3-diene (IX) is obtained and the relative quantities of (V) and (VI) are increased. The butadiene (IX) is apparently formed from compound (VIII) as previously de~cribed.~ Chemistry,' Bell and Sons Ltd., London, 1953, p. 249. Frawce, 1906, 35, 1005. C. K. Ingold, 'Structure and Mechanism in Organic 5 F. G. Kny-Jones and A. M. Ward, J . Chem. SOG., 1930, 535. R. Foss, Compt. rend., 1901, 133, 880; Bull. SOC. chim. W. Tadros and A. €3. Sakla, J . Chem. SOC., 1957, 3210.J.Chem. SOC. (C), 1970 (ii) When the bromo-compound (IV) is treated with hydrogen bromide in chloroform no reaction occurs. (iii) On treatment of bixanthenyl with bromine in carbon disulphide Conant and his co-workers obtained xanthenyl tribromide (V) . They attributed this reaction to the reactivity of the inter-ring linkage in the compound. The electron density at the xanthenyl- carbon bond in compound (VII) could well be of a similar nature. The structure of 1 ,l-bis-($-alkoxyyhenyl)-2-bromo-2- (xanthen-9-y1)ethylenes (IV; R = MeO, EtO, or PriO) c.c.), 1,l-diphenylethylene (1.8 g., 0.01 mole) in dry ether (10 c.c.) was added, and the mixture was left a t room temperature with occasional shaking (1 hr.) . The ether was recovered and the residue was digested for 15 min.with 95% ethanolic potassium hydroxide (1 g. in 30 c.c.). The mix- ture was cooled, diluted with water (50 c.c.), and extracted with ether. The ethereal layer was washed with water till free from alkali. Ether was recovered and the residue gave the olefin as crystals (2.6 g., ca. 72y0), m.p. and mixed m . ~ . ~ 164" (from 95% ethanol) (Found: C, 89.8; H, 5.6. Calc. for C,,H,,O: C, 90.0; H, 50557'~). (ii) A solution of xanthenyl chloride 12a (2.165 Q . , 0.01 i -HBr f ";i YCBr:C(C,H,R-#), YBr BrH,C*CBr (C,H,R-$) , (IV) (1) (VIII) 1 Y Br, BrCH:C(C,H,R-$), + HBr (V> (VI) IBrz I Y = Xanthen-9-yl (#-RC,H,),C:CH*CH:C(C,H,R-$), + Br, + 2HBr (IX) has been confirmed by ozonolysis to give xanthen-9- carboxylic acid and the corresponding 4,4'-di-$-alkoxy- benzophenone.Dehydrobromination of the olefins (IV) with alcoholic potassium hydroxide gave rise to the corresponding allenes, which do not show the two i.r. absorption bands at 1070 and 1950 cm.-l given by tetra- phenylallene and considered to be associated with the allenic structure.10 EXPERIMENTAL XanthenoL-To a cooled suspension of xanthone (4.90 g., 0.025 mole) in dry ether (100 c.c.), powdered lithium aluminium hydride (0.94 g., 0.025 mole) was gradually added during 30 min.; the mixture was then left a t room tem- perature for 3 hr. Water was then added dropwise to the cold solution t o decompose excess of lithium aluminium hydride. The ethereal layer was washed with water, dried (hTa,S04), and evaporated. The residue was recrystallised from 95% ethanol t o give xanthenol (4.5 g., ca.goyo), m.p. and mixed m.p. with an authentic sample l1 123". Addition of Xanthenyl Clzlovide to Asymmetvic Diaryl- ethyZenes.-This is exemplified by the preparation of 1,l- diphenyl-2- (xanthen-9-yl) ethylene. (i) Hydrogen chloride gas was passed through a cold solution of xanthenol (1-98 g., 0.01 mole) in dry ether (50 8 J. B. Conant and B. S. Garvey, J . Amer. Chem. SOC., 1927, 49, 2080. 9 W. Otting, Chew. Ber., 1954, 87, 611. cules,' 2nd edn., Wiley, New York, 1958, p, 60. l o L. J. Bellamy, ' The Infra-red Spectra of Complex Mole- mole) and 1,l-diphenylethylene (1.8 g., 0.01 mole) in dry ether (50 c.c.) was heated on a water-bath for 2 hr. The solvent was recovered, and the residue was treated with alkali as before to give the olefin, m.p.and mixed m.p.3 164". The following compounds (111) , similarly prepared, crystallised from 95% ethanol in ca. 70% yield: 1,l-bis- (p-~ethoxy~henyl)-2-(xanthen-9-yZ)ethylene, m.p. 94" (Found : C, 82.75; H, 5.8. C,,H2a0, requires C, 82.85; H, 5.7%); l,l-bis-(p-ethoxyphenyZ)-2-(xanthen-9-yl)etlzylene, m.p. 115" (Found: C, 82.65; H, 6.3. C31H2@3 requires C, 83.05; H, 6.25%) ; l,l-bis-(p-iso~ropoxy~henyl)-2-(xanthen-9-yZ)- ethylene, m.p. 169" (Found: C, 83.75; H, 6.8. C3,H,,03 requires C, 83.2; H, 6.7%) ; l,l-di-p-toZy-2-(xanthen-9-yZ)- ethylene, m.p. 115" (Found: C, 59-65; H, 5.85. C,,H,,O requires C, 89.7; H, 6.2%) ; l,l-bis-(p-bvomophenyZ)-2- (xanthen-g-yI)ethyZene, m.p. 187" (Found: C, 62.4; H, 3.75; Br, 30-7. C,,H,,Br,O requires C , 62-55; H, 3.45; Br, 30.9 yo) ; l,l-bis-(p-chZorophenyl)-2- (xanthen-9-yl)ethybne, m.p.157" (Found: C, 75.8; H, 4.1; C1, 16.6. C2,H,,C120 requires C, 75.5; H, 4.2; C1, 16.55%). Reactions of Bromine with the Xantlzenylethylenes (111) .- (a) Di-p-alkoxy-compounds. (i) Bromine (0.80 g., 0.005 mole) in chloroform (10 c.c.) was added to a solution of l,l-bis-(~-methoxyphenyl)-2-(xanthen-9-yl)ethylene (2.10 g., 0.005 mole) in the same solvent (20 c.c.) with shaking. A yellow precipitate which formed almost immediately l1 A. I. Vogel, ' A Text Book of Practical Organic Chemistry,' 2nd edn., Longmans Green, London, 1951, p. 839. l2 M. Gomberg and L. H. Cone, Annalen, 1910, 376, (a) p. 183; (6) p. 193.Org. was filtered off and washed with light petroleum (b.p. 40- 60") to give xanthenyl tribromide, m.p.and mixed lzb m.p. 164" (0.05 g.). The chloroform mother liquor was treated with aqueous sodium hydroxide (10% ; 20 c.c.), then washed with water till free from alkali. Chloroform was distilled off and the residue gave l-brom0-2,2-bis-(p-methoxyfihenyZ)-l- (xantlzen-9--yZ)ethyZe?ze as crystals (2.0 g., ca. 80%), m.p. 140-141" (from 95% ethanol) (Found: Br, 16.05. C29HL3- BrO, requires Br, 16- 1 %) . The ethanolic mother liquor was concentrated, diluted with water, and then steam-distilled ; xanthen, m.p. and mixed l3 m.p. loo", was obtained (0.1 g.). The non-steamable portion on recrystallisation from 95 yo ethanol gave starting material (0-05 g.), m.p. and mixed m.p. 94", and 2-bromo- 1, l-bis-(P-methoxypheny1)ethylene (0-15 g.), m.p.and mixed m.p. with an authentic sample 84". (ii) Repetition of experiment (i) with 1, l-bis-(p-ethosy- pheny1)-2- (xanthen-9-yl) ethylene (2.24 g., 0.005 mole) gave xanthenyl tribroniide (0.05 g.), m.p. and mixed 12b map. 164"; l-bvonzo-2,2-bis-(p-ethoxy$henyZ)- l-(xantlzen-9-yl)ethyZene (2.2 g., ca. 84y0), m.p. 151" (Found: Br, 14-85. C3,H27Br0, requires Br, 15.2%); xanthen (0.1 g.), m.p. and mixed l3 m.p. 100"; unchanged starting material (0.05 g.), m.p. and mixed 1n.p. 115"; and 2-brorno-l,l-bis-(P-ethoxyphenyl)- ethylene (0-12 g.), m.p. and mixed l5 m.p. 64". (iii) The products of the reaction of bromine with 1, l-bis- ~-isopropoxyphenyl)2-(xanthen-9-yl)ethylene (2-38 g., 0-005 mole) were xanthenyl tribromide (0.05 g.), m.p. and mixed lzb m.p. 164" ; l-b~o~o-2,2-bis-(p-isop~o~oxy~henyZ) - 1- (xanthen- 9-yZ)ethyZene (2.2 g., ca.80*8y0), crystals, m.p. 130" (from 9596 ethanol) (Found: Br, 14.9. C3,H3,Br0, requires Br, 14.4%); xanthen (0-09 g.), m.p. and mixed l3 m.p. loo", 1, 1-bis-(9-isopropoxyphenyl) 2-xanthen-9-y1)ethylene (0.05 g.), m.p. and mixed m.p. 169"; and 2-bromo-l,l-bis-(fi- isopropoxypheny1)ethylene (0.15 g.), m.p. and mixed m.p. with an authentic sample 46-47'. (iv) I n the pesence of hydvogen bvomide. Repetition of experiment (ii) with bromine (0.80 g., 0.005 mole) in chloroform (10 c.c.) and a solution of 1, l-bis-(p-ethoxy- phenyl)-2-(xanthen-9-yl)ethylene (2-24 g., 0.005 mole) in the same solvent (20 c.c.) saturated with hydrogen bromide gave xanthenyl tribromide (0.8 g.), m.p. and mixed 12b m.p.164"; 1,1,4,4-tetrakis-(~-ethoxyphenyl)buta-l ,S-diene (0.2 g.), m.p. and mixed l5 m.p. 20 1-202" ; 2-bromo- 1, l-bis- (P-ethoxy- pheny1)ethylene (0.9 g.), m.p. and mixed l5 m.p. 64"; and xanthen (0.3 g.), m.p. and mixed l3 m.p. 100". (b) l,l-DiphenyZ-2-(xanthen-9-yZ)ethyZene. (i) To a solu- tion of l,l-diphenyl-2-(xanthen-9-yl)ethylene (1.8 g., 0.005 mole) in chloroform (20 c.c.), bromine (0.8 g., 0.005 mole) in the same solvent (10 c.c.) was added with shaking. A yellow precipitate which separated almost immediately ~7as filtered off and washed with light petroleum (b.p. 40-60") to give an orange product (0.5 g.), m.p. 164", showing no depression when mixed with an authentic sample of xanthenyl tribromide. The filtrate was washed with aqueous sodium hydroxide (10% ; 20 c.c.) then with water till free from alkali.Chloroform was recovered and the residue gave unchanged starting material (0.9 g.), m.p. and mixed m.p. 164" (from ethanol). The ethanolic mother liquor was concentrated, diluted with water, and then l3 3. Heller and St. v. Kostanecki, Ber., 1908, 41, 1324. l4 F. Bergman and J. Szmuszkowicz, J . Amev. Chem. Soc., l5 W. Tadros and G. Aziz, J . Chew. SOC., 1951, 2553. 1947, 69, 1777. steam-distilled to give xanthen (0.3 g.), m.p. and mixed m.p.13 100". The non-steamable portion was extracted with ether; the solvent was recovered and the residue was recrystallised from 95% ethanol to give colourless crystals, m.p. 42" (0.4 g.), showing no depression on admixture with an authentic sample 16 of 2-bromo- 1, l-diphenylethylene.(ii) When experiment (i) was carried out a t - 5 O , xan- thenyl tribroniide, m.p. and mixed m.p.12b 164" (0.50 g.), was formed almost immediately. This reaction also gave un- changed starting material (0.9 g.), m.p. and mixed 3 m.p. 164"; xanthen (0.3 g.), m.p. and mixed l3 m.p. 100"; and 2-bromo-l,l-diphenylethylene (0.4 g.), m.p. and mixed m.p. 42". (i) When experiment (a) was repeated with 1,l-bis-(~-bromophenyl)-2-(xanthen-9-yl)- ethylene (2.58 g., 0.005 mole) the following products were obtained : xanthenyl tribroniide (0.5 g.), 1n.p. and mixed I 2 b m.p. 164"; unchanged starting material, m.p. and mixed m.p. 187" (1.0 8.); xanthen (0.2 g.), m.p. and mixed13 m.p. 100" ; and 2-bromo-l,l-bis-(~-bromophenyI)-ethylene (0-8 g.), m.p. and mixed m.p.with an authentic sample 1 7 104". (ii) When bromine (0.8 g., 0.005 mole) in chloroform (10 c.c) was added to a solution of l,l-bis-(P-chlorophenyl)-2- (xanthen-9-y1)ethylene (2.145 g., 0.005 mole) in the same solvent (20 c.c.) the following products were isolated : xanthenyl tribromide (0.5 g.), m.p. and mixed lzb m.p. 164"; unchanged starting material (1.0 g.), m.p. and mixed m.p. 157"; xanthen (0.2 g.), m.p. and mixed l3 n1.p. 100"; and 2-bromo-l,l-bis-(~-chIorophenyl)ethylene, m.p. and mixed 17 m.p. 76' (0.6 g.). 1,l -Bis- (p-methoxypheny 2) -2- (xantken- 9-y Zidene) ethylene .- A mixture of l-bromo-2,2-bis-(~-methoxyphenyl)- 1- (xanthen-9-y1)ethylene (1-0 9.) and potassium hydroxide (2.0 g.) in 95% ethanol (30 c.c.) was heated on a water-bath for 2 hr., then cooled, diluted with water (60 c.c.), and extracted with ether.The extract was washed with water till free from alkali; ether was recovered, and the residue gave crystals, m.p.l* 124" (from 95% ethanol) (Found: C, 83.15; H, 5.6. Calc. for C2gH2203: C, 83.25; H, 5.25%). 1, l-bis- (p-ethoxy$lzenyZ) 2- (xanthen-9-yZidene) - ethylene, m.p. 125" (Found: C, 82.8; H, 6.05. C3,H2,0, requires C, 83.4; H, 5.8%) and l,I-bis-(p-isop~opoxy- phenyl) -2- (xnnthen-9-yZidene)ethylene, m.p. 147" (Found : C, 84.0; H, 6.8. C&3@3 requires C, 83.55; H, 6.30/,), were obtained in ca. 75% yield. OxonoZysis of l-B~omo-2,2-bis-(p-~zetJzoxy~l~enyZ)-l- (xanthen-9-yZ)etlzyZene.-A stream of ozonised oxygen (ca. 3%) was bubbled through a cold solution of l-bromo-2,Z- bis-$-methoxypheny1)-2-(xanthen-9-yl)ethylene (1 g.) in carbon tetrachloride (200 c.c.) for 24 hr. The mixture was then decomposed with distilled water (26) c.c.), carbon tetrachloride was recovered, and the residue was extracted with ether. The extract was washed with sodium carbonate solution (20%) and evaporated, 2nd the residue was re- crystallised from 95% ethanol t o give 4,4'-dimethoxybenzo- phenone, m.p. and mixed l9 m.p. 142". The sodium carbonate solution was acidified and the precipitate was extracted with (c) DihnZogeno-covlzpo.unds. Similarly, l6 P. Lipp, Be$.., 1923, 56, 567. l7 W. Tadros, A. B. Sakla, and Y . Akhnookh, J . Chem. SOL, l8 R. Wizinger and G. Renckhoff, Helv. Chim. Acta, 1941, 24, l9 B. Jones, J . Chem. SOC., 1936, 1854. 1956, 2701. 369E.1926 J. Chem. SOC. (C), 1970 ether. Similar ozonolyses gave 4,4'-diethoxybenzophenone, m.p. crystallised from 30% ethanol to give xanthen-9-carboxylic and mixed l9 m.p. 13 lo, and 4,4-di-isopropoxybenzo- acid, m.p. and mixed 2o m.p. ZOO". phenone, m.p. and mixed l9 m.p. 74", each accompanied by xanthen-9-carboxylic acid. 1959, 53, 3246j). [0/133 Received, January 28th, 19701 The solvent was recovered and the residue was re- 20 R. Lutz and J. Rosicky, Swiss Pat. 326,533 (Chem. Abs.,
ISSN:0022-4952
DOI:10.1039/J39700001923
出版商:RSC
年代:1970
数据来源: RSC