Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2002-05-29
2003-11-04
Rotman, Alan L. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C549S513000, C558S044000
Reexamination Certificate
active
06642395
ABSTRACT:
TECHNICAL FIELD
This invention relates to an acetalsulfonate derivative, a process for producing the same, and a process for producing a styrene oxide derivative using an acetalsulfonate derivative or a mandelic acid derivative as a starting material.
The starting materials, intermediates and final products of this invention can also be optically active substances. The compounds obtained according to this invention are useful as raw materials for medicines, agricultural chemicals, and the like and further, can give, in good yield, styrene oxide derivatives and ethanolamine derivatives which are useful as raw materials for medicines, agricultural chemicals, and the like.
The acetalsulfonate derivative of this invention can be easily converted into the corresponding styrene oxide derivative by epoxidation. The styrene oxide derivative thus obtained can be converted into corresponding ethanolamine derivatives by a reaction with various amines.
BACKGROUND ART
With regard to a process for producing an acetalsulfonate derivative, there can be considered, for example, a process which comprises converting an ethanediol derivative into a sulfonate derivative, followed by protection with an acetal. This process, however, has a problem in that it has a poor selectivity in converting an ethanediol derivative into a sulfonate derivative and hence an intended product cannot be isolated in high yield (J. Org. Chem., 21, 1260 (1956))
As to a process for producing a styrene oxide derivative, there is well known a process which comprises epoxidizing a 2-hydroxy-2-phenylethyl sulfonate derivative or a 2-hydroxy-2-phenylethyl halide derivative by use of a base (J. Org. Chem. 21,597 (1956)).
However, the 2-hydroxy-2-phenylethyl sulfonate derivative or the 2-hydroxy-2-phenylethyl halide derivative which are the materials used in the above-mentioned process are difficult to obtain in high purity. Accordingly, the epoxidation reaction has previously been conducted by using, as such, the above-mentioned derivatives mingled with their positional isomers, i.e., a 2-hydroxy-1-phenylethyl sulfonate derivative or 2-hydroxy-1-phenylethyl halide derivative, and a disulfonate derivative or dihalide derivative (Synthesis, 1985,983) (U.S. Pat. No. 4391826). In this process, when disulfoante derivative or dihalide derivative is mingled into the starting material, it is apt to cause difficulty in purification of the product, resulting in lowering of the yield. Still, when a position isomer is mingled, though the process has no problem in producing a racemic substance, it is apt to cause lowering of optical purity in case an optically active substance is produced.
Although an acetalsulfonate derivative and styrene oxide derivative are useful as an intermediate for medicines and agricultural chemicals, previous processes for producing them have problems as described above. Accordingly, a development of an industrial process for producing the derivatives has been eagerly awaited which is highly safe, simple and economical and gives good yield.
DISCLOSURE OF THE INVENTION
The present inventors have made extensive studies to achieve the above-mentioned object. As the result, the inventors have found that an acetalsulfonate derivative can be produced in high purity and high yield by using an inexpensive mandelic acid derivative as a starting material and that a styrene oxide derivative can be produced in high purity and high yield by using an acetalsulfonate derivative or a mandelic acid derivative as a starting material. This invention has been attained on the basis of the above finding.
Thus, the first aspect of this invention relates to an acetalsulfonate derivative which is represented by the following formula (1)
wherein R
1
and R
2
can be same as or different from each other and each denote a hydrogen atom, halogen atom, hydroxyl group, a straight or branched chain alkyl group having 1-4 carbon atoms optionally substituted with a halogen, a straight or branched chain alkoxy group having 1-4 carbon atoms optionally substituted with a halogen, amino group optionally substituted, nitro group or trifluoromethyl group, or R
1
and R
2
together denote a lower alkylenedioxy group; R
3
denotes 3,4,5,6-tetrahydro-2H-pyran-2-yl group or 1-methoxy-1-methylethyl group, and R
4
denotes a straight or branched chain alkyl group having 1-4 carbon atoms or a phenyl group optionally substituted.
The second aspect of this invention relates to a process for producing an acetalsulfonate derivative represented by the above formula (1) which comprises:
(a) a first step of esterifying a mandelic acid derivative represented by the following formula (2)
wherein R
1
and R
2
are the same as defined above,
(b) a second step of protecting by an acetal a mandelic ester derivative represented by the following formula (3) obtained in the first step,
wherein R
1
and R
2
are the same as defined above and R
5
denotes a straight or branched chain alkyl group having 1-4 carbon atoms,
(c) a third step of reducing an acetal derivative represented by the following formula (4) obtained in the second step,
wherein R
1
, R
2
, R
3
and R
5
are the same as defined above, and
(d) a fourth step of reacting with a sulfonyl chloride derivative an ethanediol derivative represented by the following formula (5) obtained in the third step,
wherein R
1
, R
2
and R
3
are the same as defined above.
The third aspect of this invention relates to a process for producing a styrene oxide derivative represented by the following formula (6)
wherein R
1
and R
2
are the same as defined above, which comprises:
(e) a deprotecting step of deprotecting the acetalsulfonate derivative represented by the following formula (1)
wherein R
1
, R
2
, R
3
and R
4
are the same as defined above, and
(f) an epoxidizing step of epoxidizing a sulfoante derivative represented by the following formula (7) obtained in the above-mentioned deprotecting step, with the aid of a base catalyst,
wherein R
1
, R
2
and R4 are the same as defined above.
The fourth aspect of this invention relates to a process for producing the styrene oxide derivative represented by the above-mentioned formula (6) from a mandelic acid derivative through serial processes, said styrene oxide derivative being represented by the following formula (6),
wherein R
1
and R
2
are the same as defined above, which comprises:
(a) a first step of esterifying a mandelic acid derivative represented by the following formula (2)
wherein R
1
and R
2
are the same as defined above,
(b) a second step of protecting by an acetal a mandelic ester derivative represented by the following formula (3) obtained in the above-mentioned first step
wherein R
1
R
2
and R
5
are the same as defined above,
c) a third step of reducing an acetal derivative represented by the following formula (4) obtained in the above-mentioned second step
wherein R
1
, R
2
, R
3
and R
5
are the same as defined above,
(d) a fourth step of reacting with a sulfonyl chloride derivative an ethanediol derivative represented by the following formula (5) obtained in the above-mentioned third step
wherein R
1
, R
2
and R
3
are the same as defined above,
(e) a deprotecting step of deprotecting an acetalsulfonate derivative represented by the following formula (1) obtained in the above-mentioned fourth step
wherein R
1
, R
2
, R
3
and R
4
are the same as defined above, and
(f) an epoxidizing step of epoxidizing a sulfonate derivative represented by the following formula (7) obtained in the above-mentioned deprotecting step, with the aid of a base catalyst
wherein R
1
, R
2
and R
4
are the same as defined above,
Some embodiments of this invention are described further in detail below.
The acetalsulfonate derivative of this invention is represented by the above-mentioned formula (1), wherein R
1
and R
2
can be same as or different from each other and each denote a hydrogen atom, halogen atom, hydroxyl group, a straight or branched chain alkyl group having 1-4 carbon atoms optionally substituted with a halogen, a straight or branched chain a
Kobayashi Yoshimasa
Mori Hiroyuki
Morita Hikari
Covington Raymond
Mitsubishi Rayon Co. Ltd.
Rotman Alan L.
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