569
J. Org. Chem. 1986,51, 569-571 and 1.6 g of NaH2P04in 20 mL of water and 5.0 mL (5.2 x mol) of 35% HzOz,keeping the temperature at 10 "C with water cooling. Oxygen evolved from the solution was monitored until the end of the reaction (about 1 h) with a bubbler connected to the apparatus. A small amount (-0.5 g) of NaZSO3was added to destroy the unreacted HOC1 and HzOz. Acidification with 10% aqueous HC1 afforded 7.0 g (95%) of cinnamic acid, as crystalline solid, mp 131-133 "C (lit.13mp 133 "C). TLC and GLC analyses revealed not valuable impurities. 'H NMR (CDCl,) 6 6.41 (d, 1 H), 7.17-7.69 (m, 5 H), 7.73 (d, 1 H), 11.85 (s, 1 H). Procedure B. It differs from procedure A since a 5:l molar ratio H,O,-aldehyde is used, and the p H of the medium is lowered to about 2.0 by cautious addition of 37% HC1 to the NaHzP04buffer. The reactions are faster than those of procedure A.
General Oxidation Procedure with NaC1O2-Me2SO. A solution of 8.0 g (7.0 X mol) of 79% NaCIOz (iodometric titration) in 70 mL of HzO was added dropwise in 2 h a t room temperature to a stirred mixture of 6.6 g (5.0 X mol) of cinnamaldehyde in 50 mL of MezSO and of 1.6 g of NaH2P04in 20 mL of water. The mixture was left overnight at room temperature, then 5% aqueous solution of NaHCO, was added. The aqueous phase was extracted 3 times with CHZCl2and acidified with 10 M aqueous HC1, and the precipitated cinnamic acid was collected: 7.0 g (95% yield), mp 130-132 "C. TLC and GLC analyses revealed no appreciable impurity nor contamination from Me,SO or dimethyl sulphone.
General Oxidation Procedure with NaC10,H2NS03H. The general procedure A was followed, but 6.3 g (6.5 X mol) of sulfamic acid as scavenger dissolved in 60 mL of water and 6.6 g (5 X lo-' mol) of cinnamaldehyde in 50 mL of tert-butyl alcohol was used. After 2 h at room temperature, a crude product was isolated and purified by column chromatography (silica gel; 8:2 ethyl ether-n-hexane): 4.4 g (60%) of cinnamic acid, mp 131-133 "C, 1.64 g (25%) of cinnamonitrile, mp 20 "C (lit.', mp 20-21 "C), and 0.1 g (1.2%) of tert-butyl cinnamate, bp 70 "C (0.1 torr) (lit.', bp 140 "C (9 torr)).
dine-4-carboxaldehyde,812-85-5;thiophene-2-carboxaldehyde, 98-03-3; 5-nitro-2-furancarboxaldehyde,698-63-5; furan-2carboxaldehyde, 98-01-1; pyrole-2-carboxaldehyde,1003-29-8; hydroquinone, 123-31-9;methyl ppidine-4-carboxylate,2459-09-8; 5-nitro-2-furancarboxylic acid, 645-12-5; 2-furancarboxylic acid, 88-14-2; maleic acid, 110-16-7; cyclohexene-3-carboxaldehyde, 100-50-5;cyclohexene-3-carboxylicacid, 4771-80-6; thiophene-2carboxylic acid, 527-72-0.
Synthesis of Novel GH-1,3-OxazineDerivatives with Perfluoroalkyl Substituents Isao Ikeda,* Mitsuhiro Umino, and Mitsuo Okahara Department of Applied Chemistry, Faculty of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka, Japan 565 Received October 2, 1985
Recently, the reactions of perfluoro-2-methylpent-2-ene ( 1),1,2a dimer of hexafluoropropene, with various nucleo-
philes such as alcohols, carboxylic acids, amines and thiols (or their conjugate bases) have been inve~tigated,,,~ and it has been reported that the reaction proceeded via an apparent nucleophilic substitution reaction. The reaction of 1 as a 1,3-bidentate electrophile has been studied in recent years and various heterocycles with five-, six-, seven-, and eight-membered rings resulted from the reactions with bidentate nucleophiles such as N,N-dimethylhydra~ine,~ acylhydrazones,6 benzoylacetonitrile, benzoyltrifluoroacetone, acetoacetanilide, catechol, ophenylenediamine, o-aminophenol, and sali~ylaldehyde.~-~ In the present work, new 6H-1,3-oxazines with perfluoroalkyl substituents (3a-d) were obtained in moderate yields from 2 and 1 in the presence of base.
Results and Discussion
When a tetrahydrofuran (THF) solution of 1 was treated Acknowledgment. We are grateful to Dr. R. Santi for with a T H F suspension of the sodium salt of 2a, a single helpful discussions and to Mrs. T. Fiorani for determinaoxazine was cleanly formed as demonstrated by "F NMR. tion of the mass spectra. The spectrum of the product showed the presence of only Registry No. (E)-C6H5CH=CHCH0, 14371-10-9; ( E ) one pentafluoroethyl, one trifluoromethyl, and one diC6H,CH=C(CH,)CHO, 15174-47-7; (E)-C,HbCH=C(Cl)CHO, fluoromethylene group. However, spectral data did not 99414-74-1; (E)-C6H5CH=C(Br)CH0, 99686-39-2; (E)-orule out one of the two possible structures (3a and 4a). To 02NC6H,CH=CHCHO, 66894-06-2; P-CH~CONHC~H~CHO, distinguish between these two possibilities, the product was 122-85-0; p-HOC6H4CHO, 123-08-0; (E)-CH&H=CHCHO, 123-73-9; (E)-CZHSOCH=C(CH3)CHO, 62055-46-3; (2)- treated with l,l-dimethylhydrazine.'O The I9F NMR spectrum of the resulting compound showed the disap(CH,),C=CH(CH2)2C(CH3)=CHCHO,106-26-3;(E)-(CH,)zC= pearance of two fluorine atoms from the original product CH(CH2)2C(CHJ=CHCHO, 141-27-5;CH3(CH2)4CHO,66-25-1; (3a or 4a);a band assigned to carbonyl absorption (1720 (E)-C6H&H=CHCO2H, 140-10-3;(E)-C6H,CH=C(CH,)CO2H, 1895-97-2;(E)-C6H&H=C(Cl)CO,H, 705-55-5; (E)-CBH~CH= cm-l) appeared in the IR spectrum. Furthermore, the mass C(Br)CO2H,15894-30-1;(E)-O-~~NC~H,CH=CHCO~H, 882-06-4; spectrum of the dimethylhydrazine-treated product disC~HSCZCCO~H, 637-44-5; P-CH~CONHC~H~CO~H, 556-08-1; played a very strong fragment of relative abundance of 69 P-CH~SOC~H~CO~H, 33963-58-5; P-CH~SO~C~H~CO~H, 4052-30-6; ( E )- CH3( CHz)2CH=C HC02H , 13419-69-7; ( E )- CH3CH= CHCOZH, 107-93-7; 2-HO-3-CH3OC6H,COzH, 877-22-5; ( E ) (1) Du Pont US. Patent 2918501, 1959. (CH3)2C=CH( CH2)SC(CH,)=CHC02H, 4698-08-2; (2)(2) Dresdner, R. D.; Tlumac, F. N.; Young, J. A. J . Org. Chem. 1965, (CH3)2C=CH(CHz)zC(CH3)=CHC02H, 4613-38-1; C6H5C
