Organic compounds -- part of the class 532-570 series – Organic compounds – Sulfur containing
Reexamination Certificate
2001-09-21
2003-07-08
Vollano, Jean F. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Sulfur containing
C568S034000
Reexamination Certificate
active
06590126
ABSTRACT:
The present invention relates to industrial processes for the production of diphenyl sulfone compounds represented by Formula (II) and useful as developers for leuco dyes to be used in thermal recording papers, and in more detail, to processes for the efficient production of the said diphenyl sulfone compounds by the recovery and reuse of harmful halogen compounds without discharging them into the environment.
BACKGROUND ART
Processes for the preparation of diphenyl sulfone compounds of Formula (II) are disclosed in Japanese Patents Laid-open Nos. Sho 58-20493, Sho 58-82788, Sho 60-13852 and Sho 60-56949, that 4,4′-dihydroxydiophenyl sulfone is reacted with a halogen compound, such as alkyl halide, in a polar solvent, such as dimethylformamide or alcohol, in the presence of an alkali. These processes have a drawback of difficulty to improve the selectivity of reactions because of the use of solvents that dissolve reaction reagents and products well. There was a problem that noticeable amounts of diether derivatives, i.e., 4,4′-disubstituted hydroxydiphenyl sulfones, are produced as byproducts.
WO 91/11433 has reported that a reaction of a mole of 4,4′-dihydroxydiphenyl sulfone with an alkyl halide in the presence of 1.5 to 3 moles of alkali in 0.3 to 1.5 parts by weight of an aqueous solvent to a part by weight of 4,4′-dihydroxydiphenyl sulfone results in satisfactory selectivity and yield. However, when alkyl chlorides are used, it takes a long time to complete the reaction because of their low reactivity. Besides, alkyl iodides are expensive. Therefore, alkyl halides able to use in industry are practically limited to alkyl bromides. The said WO patent reports only examples of using alkyl bromides.
If an alkylation is carried out using an alkyl bromide under the above reaction conditions, crystals are deposited as the reaction proceeds. The inside of the system becomes viscous and heterogeneous, resulting in insufficient stirring. Therefore, there is a problem of incompletion of the reaction.
Of compounds of Formula (II) useful as developers for leuco dyes to be used in thermal recording papers, compounds where R is isopropyl are produced using isopropyl bromide, which is hardly produced domestically. Therefore it is difficult to procure the starting material stably.
It is an object of the present invention to provide industrial processes for the production of diphenyl sulfone compounds of Formula (II) by using alkylating agents that are supplied stably, instead of alkyl bromide, with productivity, economical efficiency and safety.
DISCLOSURE OF THE INVENTION
The inventors of the present invention studied various alkylations, such as those with alkyl sulfates, by addition of unsaturated hydrocarbons, and of using alkyl chlorides or alkyl iodides. As a result, it was found that use of alkyl iodides and the like could greatly shorten production times, and that almost all of alkyl iodides and the like used in the reactions could be recovered as inorganic iodide salts. An iodine recovery step in which iodine is recovered from manufacturing waste water containing the salts and reacted with an alcohol to self-produce an alkyl iodide or the like, is incorporated in the production process. Then, iodine is completely recovered for reuse. The process is more improved in productivity and economic efficiency than those of the prior art. Thus, the present invention has been completed.
The present invention relates to (1) an industrial process for the production of diphenyl sulfone compounds of Formula (II)
(wherein, R is straight or branched chain alkyl, straight or branched chain alkenyl, straight or branched chain alkynyl, or optionally substituted cycloalkyl), characterized in that 4,4′-dihydroxydiphenyl sulfone is reacted with a compound represented by Formula (I)
RI
(wherein, R is as defined above) in the presence of a base at reaction temperature of 70 to 110° C., preferably 70 to 90° C.
It relates to (2) an industrial process for the production of diphenyl sulfone compounds according to (1), in which 0.8 to 2 moles of a compound of Formula (I) and 2 to 4 moles of a base are used to a mole of 4,4′-dihydroxydiphenyl sulfone, and the concentration of the base is made 20 to 50% by weight with water used as a solvent.
It relates to (3) an industrial process for the production of diphenyl sulfone compounds according to (1) or (2), in which a reaction time is 4 to 15 hours.
It relates to (4) an industrial process for the production of diphenyl sulfone compounds according to one of (1) to (3), in which a compound of Formula (I) is where R is isopropyl.
It relates to (5) an industrial process for the production of diphenyl sulfone compounds represented by Formula (II)
(wherein, R is as defined above), characterized by containing an iodine recovery step that 4,4′-dihydroxydiphenyl sulfone is reacted with a compound of Formula (I)
RI
(wherein, R is as defined above) in the presence of a base, iodine is recovered from iodides contained in waste water, and the recovered iodine is reacted with an alcohol corresponding to a compound of Formula (I) to be used for the reaction, to give a compound of Formula (I).
It relates to (6) a process for the production of diphenyl sulfone compounds according to (5), in which a step is further incorporated that iodine is recovered from waste water discharged when a compound of Formula (I) is produced by a reaction of the previously recovered iodine with an alcohol corresponding to the compound of Formula (I) to be used for the reaction, and reused for the production of compounds of Formula (I).
It relates to (7) an industrial process for the production of diphenyl sulfone compounds according to (5) or (6), in which 4,4′-dihydroxydiphenyl sulfone is reacted with a compound of Formula (I) in the presence of a base at 70 to 110° C., preferably 70 to 90° C.
It relates to (8) an industrial process for the production of diphenyl sulfone compounds according to one of (5) to (7), in which 0.8 to 2 moles of a compound of Formula (I) and 2 to 4 moles of a base are used to a mole of 4,4′-dihydroxydiphenyl sulfone, and the concentration of the base is made 20 to 50% by weight with water used as a solvent.
It relates to (9) an industrial process for the production of diphenyl sulfone compounds according to one of (5) to (8), in which a reaction time is 4 to 15 hours.
It relates to (10) an industrial process for the production of diphenyl sulfone compounds according to one of (5) to (9), in which a compound of Formula (I) is where R is isopropyl.
Examples of compounds of Formula (I) used in the methods of the present invention include alkyl iodides such as methyl iodide, ethyl iodide, n-propyl iodide, isopropyl iodide, n-butyl iodide, isobutyl iodide, sec-butyl iodide, pentyl iodide, hexyl iodide, heptyl iodide and octyl iodide; alkenyl iodides such as allyl iodide; and cycloalkyl iodides such as cyclohexyl iodide.
In the present invention, compounds of Formula (I) (hereinafter abbreviated as alkyl iodides and the like) are preferably used 0.8 to 2 equivalents, more preferably 1.0 to 1.6 equivalents, to 4,4′-dihydroxydiphenyl sulfone.
Generally, alkyl iodides and the like are more reactive than alkyl bromides and the like, so that selectivity is not good. For example, production rates of monoalkyl and dialkyl products of 4,4′-diphenyl sulfone are reduced. The inventors of the present invention, however, found out that, if water is used as a reaction solvent, selectivity is not deteriorated, because solubility of alkyl iodides and the like to water is lower than that of alkyl bromides and the like (for example, solubility of isopropyl bromide: 0.381 g/100 g of water; and isopropyl iodide: 0.139 g/100 g of water).
As describe above, solubility of alkyl bromides and the like to water is larger than that of alkyl iodides and the like. Thus, there is a problem that alkyl bromides and the like are susceptible to hydrolysis by bases that are not forming salts with 4,4′-dihydroxydiphenyl sulfone. Therefore,
Hanzawa Masayuki
Hidaka Tomoya
Kaeriyama Minoru
Kawabe Toru
Sanpei Syuichiro
LaPointe Dennis G.
Mason Law, P.A.
Nippon Soda Co. Ltd.
Vollano Jean F.
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