Kazuo Kodaira

The electrochemical fluorination of α-alkyl-substituted carboxylic acids

Abstract The electrochemical fluorination of acid chlorides and methyl esters of the α-alkyl-substituted carboxylic acids (2-methyl-n-valeryl chloride, 2-methyl-n-caproyl chloride, 2-methyl-n-enanthyl chloride, 2,3-dimethyl-n-buturyl chloride, methyl 2-ethyl-n-valerate, 2-n-propyl-n-valeryl chloride, 2-ethyl-n-caproyl chloride and methyl 2-n-butyl-n-caproate) was conducted to give a series of the substituted perfluorooxolanes and perfluorooxanes fluorides in good yields. The physical properties of the new compounds obtained are reported together with some of the 19 F nmr data.

Fluorination of 2-alkyl-substituted oxanes. The synthesis and purification of perfluoro(2-alkyl-substituted oxane)s

Abstract Five kinds of 2-alkyl-substituted oxanes like 2-ethyloxane, 2-n-propyloxane, 2-iso-propyloxane, 2-n-butyloxane and 2-n-amyloxane were fluorinated electrochemically to give the corresponding perfluoro(2-alkyloxane)s. The perfluoro(2-alkyloxane)s were obtained in good yields from these starting materials together with isomeric perfluoro(2-alkyloxolane)s, perfluoro(2-alkyl-5-methyloxolane)s and perfluoro(dialkyl ether)s. The purification of the perfluoro(2-alkyloxane)s which contained small amounts of isomeric perfluoro(2-alkyloxolane)s was successfully achieved by recovering the former unreacted after treating these mixture with anhydrous aluminum chloride at 150 /sR 160 °C during /sR 48 hrs in order to convert the latter into the easy-separable perfluoro(2,5,5- trichloro-2-alkyloxolane)s. Small quantities of new perfluoro(5,5-dichloroalkanoyl chloride)s were also among the chlorination products. The spectroscopic data as well as the physical properties of these new fluorination products, and perfluoro(2,5,5-trichloro-2-alkyloxolane)s and perfluoro(5,5-dichloroalkanoyl chloride)s are presented.

Electrochemical fluorination of chlorine-containing amines

Abstract The electrochemical fluorination of chlorine-containing ethers has been studied. In general, it was found that a chlorine bonded to an a -carbon atom in the ethers was readily removed during electrochemical reaction in anhydrous hydrogen fluoride, whilst a chlorine bonded to the β-carbon atom was retained to yield β-chlorinated polyfluoroethers. Through the use of this method, several new chloropolyfluoroethers, e.g. 2-chloro-1,1,2,2-tetrafluoroethyl difluoromethyl ether, 2,2-dichloro-1,1,2-trifluoroethyl trifluoromethyl ether 2,2-dichloro-1,1,2-trifluoroethyl difluoromethyl ether, 2,2-dichloro-1,1,2-trifluoroethyl chlorodifluoromethyl ether, 2-chloro-1,1,2,2-tetrafluoroethyl chlorodifluoromethyl ether and 2,2-trichloro-1,1-difluoroethyl trifluoromethyl ether, have isolated and characterized.

Synthesis and polymerization of some ethynyl trifluoromethyl napthhalenes

Abstract Some bromonaphthoic acids were fluorinated with SF4 to bromo(trifluoromethyl)naphthalenes. Although a reaction of Grignard reagent of one of the bromides with Cl2C=CF2 gave low yield of a (dichlorofluorovinyl) (trifluoromethyl) naphthalene, lithio derivatives gave the desired ethynyl(trifluoromethyl) naphthalenes in improved yields after subsequent eliminations of the vinylic halogens with n –butyllithium. Polymerization of the acetylenes was carried out with photo-activated W(CO)6 catalyst to yield high-molecular-weight polymers.

Synthesis of some ethynyltrifluoromethylfurans and their polymerization

Abstract Some trifluoromethyl group substituted ethynylfurans were prepared according to the method of Okuhara. However, dichlorofluorovinylation of lithiated 2,3-bis(trifluoromethyl)- furan did not undergo so smoothly because of the electron- withdrawing trifluoromethyl groups and the initially substituted dichlorofluorovinyl group. Thermal, γ-ray induced, or oxidation polymerizations were investigated, and 1,4-diethynyl- 2,3-bis(trifluoromethyl)furan thermally polymerized to give an insoluble polymer in a violent exothermal reaction.

Some unsymmetrical azo compounds as initiators in radical polymerization

Abstract 2-Propylazodiphenylmethane (PAD), cyclohexylazodiphenylmethane (CAD), benzylazodiphenylmethane (BAD) and 1-phenylethylazodiphenylmethane (PEAD) were prepared. These materials decomposed through first order reactions. The ease of decomposition increased in the order: CAD

Use of 1,1-dichloro-2,2-difluoroethylene in synthesis of fluorine-containing aryl acetylene

Abstract Recently polyfluoroacetylene and polydifluoroacetylene have been proposed as possible semiconducting meterials, particularly after doped with electron donors. Since their monomers are difficult to handle and their polymerization is unknown, polyphenylacetylene having fluorine atoms may be of considerable interest in evaluating the role of fluorine in this area. In connection with such a project, synthesis of some fluorine-containing phenylacetylenes was performed applying the method of introduction of the ethynyl group using CF 2 CCl 2 (I). The yields of III ranged from 50 to 80% except for the cases where m-bis(trifluoromethyl)benzene was used as the starting material. Lithiation of p-bis(trifluoromethyl)benzene and subsequent reaction with I occurred readily. In the cases where m- and p-fluoro- and m- and p-trifluoromethylbromo- benzene were used, the route via Grignard reagents gave higher yields of III (by 11–32%). However, o-trifluoromethyl- phenylmagnesium bromide did not react with I. The reaction of pentafluorophenylmagnesium bromide with I was also very slow. The proportion of C 6 F 5 Cl and C 6 F 5 CFCCl 2 obtained from the reaction of pentafluorophenyllithium with I was sensitive to the reaction conditions, the best yield of C 6 F 5 CFCCl 2 being 59%. The conversion of III to IV was performed in high yield at low temperatures, though the yield of pentafluorophenylacetylene was only about 50% due to the concurrent substitution at the para position, p-RC 6 F 4 CCH was obtained in ca 80% yield by treatment with 3 equiv of RLi. Some of the fluorine-containing diphenyldiacetylenes obtained by oxidative coupling from the stated terminal acetylenes showed solid-state polymerizability whereas the corresponding compounds containing no fluorine did not. other acetylenic compounds such as C 6 F 5 CCCCH will also be reported.