JP5774507B2 - C-11 labeled methyl iodide synthesizer - Google Patents

Description

  The present invention relates to an apparatus for synthesizing C-11 labeled methyl iodide.

  In the synthesis of C-11-labeled methyl iodide by the conventional liquid phase method, C-11-labeled carbon dioxide and lithium aluminum hydride are reacted in THF solvent, and after removing THF, further aqueous hydroiodic acid solution To obtain C-11 labeled methyl iodide. By heating the reaction vessel to about 100 to 200 ° C., the resulting C-11 labeled methyl iodide is transferred to the next step as a gas. Since the labeling reaction using C-11-labeled methyl iodide in the next step often dislikes water, a column packed with diphosphorus pentoxide or the like is installed on the transfer line for water removal. When a large amount of water is fed into such a column, C-11-labeled methyl iodide is also captured together with the column, leading to a decrease in the yield of C-11-labeled methyl iodide.

  As a countermeasure, in the above synthesis method, for example, a reactor provided with a cooling pipe as shown in FIG. 3 is used. 3 includes a raw material inlet 103 for introducing a lithium aluminum hydride solution 102, a gas inlet 105 for introducing C-11 labeled carbon dioxide for blowing into the lithium aluminum hydride, and a C-11 labeled. And a product outlet 107 for taking out methyl iodide. A spiral cooling pipe 109 for flowing cooling water is installed above the liquid level of the lithium aluminum hydride solution 102 accommodated in the reactor 100. The water contained in the C-11 labeled methyl iodide is cooled by the cooling pipe 109 to form water droplets, so that the C-11 labeled methyl iodide with a small amount of water is sent from the product outlet 107. In addition, since this kind of reactor which is illustrated as the reactor 100 is usually produced by custom order, there is no prior art document information.

  However, the specially shaped reactor as described above is expensive, and is not suitable for disposable use, for example. In this type of reaction apparatus, it is preferable that a general-purpose reaction container having a simple structure can be used so that the container can be disposable.

  Accordingly, an object of the present invention is to provide a C-11-labeled methyl iodide synthesizer that can use a general-purpose reaction vessel.

An apparatus for synthesizing C-11-labeled methyl iodide according to the present invention comprises a bottomed cylindrical reaction vessel having only one opening provided at one end and containing a lithium aluminum hydride solution; A heating means for heating the bottom, a raw material gas introducing means for blowing C-11-labeled carbon dioxide into the lithium aluminum hydride solution in the reaction vessel through the opening, and C-11-labeled methyl iodide produced in the reaction vessel has between product acquisition means for withdrawing from the reaction vessel through the opening in the state, the flanged member attached to the outer wall surface of the counter-reaction container device, the insertion opening of the bottom side is inserted from above the reaction vessel, the bottom to the insertion opening And a support for supporting the bowl-shaped member attached to the reaction vessel with the side inserted from below, and the heating means sends hot air to the bottom of the reaction container protruding downward from the insertion port, The member is inserted The upper and lower sides of the inlet are partitioned to block the flow of hot air above the insertion port .

  A bowl-shaped member is attached to the reaction vessel of this synthesis apparatus, and the opening side and the bottom side are partitioned on the outer wall surface of the reaction vessel. According to this configuration, the heat to the bottom side of the reaction vessel supplied from the heating means is blocked by the bowl-shaped member and is not easily transmitted to the opening side of the reaction vessel. Therefore, the opening side of the reaction vessel is maintained at a relatively low temperature, and as a result, the water contained in the C-11-labeled methyl iodide is cooled by the wall surface or the like on the opening side of the reaction vessel and is easily formed into water droplets. Thus, the opening side of the reaction vessel partitioned by the bowl-shaped member functions as a cooling means for liquefying the water contained in the C-11 labeled methyl iodide. Therefore, a cooling tube or the like installed inside the reaction vessel can be omitted, and a general-purpose reaction vessel having only one end opened can be used.

Moreover, the synthesis apparatus of the present invention includes a support body that has an insertion port through which the bottom side of the reaction vessel is inserted from above and supports the bowl-shaped member from below . According to this structure, if it is a diameter smaller than an insertion port, it will respond | correspond to the reaction container of various diameters, and the selection range of reaction container will spread.

Further, the heating means sends hot air to the bottom of the reaction vessel extending downward from the insertion port . According to this configuration, there is a concern that the hot air also flows to the opening side of the reaction vessel and the temperature on the opening side rises. Is more suitably exhibited.

  According to the present invention, it is possible to provide a C-11-labeled methyl iodide synthesizer capable of using a general-purpose reaction vessel.

It is sectional drawing which shows one Embodiment of the synthesizing | combining apparatus of this invention. It is sectional drawing which shows the vial bottle of the synthesizer of FIG. It is sectional drawing which shows the reaction container of the conventional synthesis apparatus.

  Hereinafter, embodiments of a synthesis apparatus according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a C-11 labeled methyl iodide synthesis device 1 includes a heating device 5 for heating the bottom side of a glass vial (reaction vessel) 3. The heating device 5 includes a flange (support) 9 having a circular insertion port 7 on the upper surface, and a blower (heating means) 11 that sends hot air from the side surface side of the flange 9 toward the interior of the flange 9. And. The bottom side 3a of the vial 3 is inserted into the insertion port 7 from above. The bottom side 3 a of the vial 3 protrudes downward from the insertion port 7 toward the inside of the flange 9. In this state, the hot air from the blower unit 11 is sent toward the bottom side 3a of the vial 3 so that the bottom side 3a of the vial 3 can be heated.

  As shown in FIG. 2, the vial 3 is a commercially available general-purpose product, and has a bottomed cylindrical shape in which only one opening 13 is provided at the upper end. The cap 15 of the vial 3 has a rubber stopper 15a. The injection needles 31 and 33 pass through the rubber stopper 15 a and are inserted into the vial 3 through the opening 13. The lower end of the injection needle (raw material gas introducing means) 31 is located near the bottom of the vial 3. The lower end of the injection needle (product acquisition means) 33 is located near the opening 13 of the vial 3. A bowl-shaped member 21 is attached to the barrel outer wall surface 17 at the center of the vial 3. The bowl-shaped member 21 is a circular member made of, for example, resin (PEEK or the like), and partitions the bottom side 3a and the opening side 3b of the vial 3. The barrel outer wall surface 17 at the center of the vial 3 and the bowl-shaped member 21 are in close contact with each other with an O-ring 23 interposed therebetween.

  As shown in FIG. 1, the diameter of the insertion port 7 is smaller than the outer diameter of the bowl-shaped member 21 and larger than the diameter of the vial 3. When the bottom side 3a of the vial 3 is inserted into the insertion port 7 with the bowl-shaped member 21 attached, the bowl-shaped member 21 is supported on the upper surface of the bowl 9 from below, and the vial 3 and the bowl-shaped member The position of 21 is fixed.

A method for synthesizing C-11 labeled methyl iodide using the synthesizer 1 as described above is as follows. As shown in FIG. 1, a THF (tetrahydrofuran) solution of LiAlH ₄ (lithium aluminum hydride) dispensed in a syringe is introduced into the bottom of the vial 3 of the synthesizer 1 from the outside through the upper rubber stopper 15a. To do. While the bottom 3a of the vial 3 is cooled by a predetermined cooling means, ¹¹ CO ₂ (C-11 labeled carbon dioxide) gas is blown into the solution through the injection needle 31, and is collected and reacted. Thereafter, after removing the THF solvent, a hydroiodic acid aqueous solution is introduced into the vial 3 through the injection needle 31 and reacted to produce C-11-labeled methyl iodide. C-11-labeled methyl iodide is vaporized by heating (100 to 200 ° C.) of the blower unit 11. C-11 labeled methyl iodide is discharged from the injection needle 33 as a gas and transferred to the next step. On the transfer line downstream of the injection needle 33, a column (not shown) filled with diphosphorus pentoxide or the like is installed for removing water.

  Then, the effect by the synthesizing | combining apparatus 1 is demonstrated.

  When a large amount of water is sent to the column on the transfer line, C-11 labeled methyl iodide is also captured together with the column, resulting in a decrease in the yield of C-11 labeled methyl iodide. Therefore, it is preferable that the C-11 labeled methyl iodide discharged from the vial 3 contains as little water as possible. For this reason, conventionally, there can be considered a method in which a cooling pipe is provided above the liquid level in the reaction vessel (here, in the vial 3), and the water in the C-11-labeled methyl iodide is converted into water droplets with cooling water. .

  On the other hand, in the synthesizing apparatus 1, the bowl-shaped member 21 is attached to the vial 3, and the opening side 3 b and the bottom side 3 a are partitioned at the body outer wall surface 17 of the vial 3. Thereby, the hot air from the ventilation part 11 to the bottom side 3a is interrupted by the bowl-shaped member 21, and hardly flows to the opening side 3b. Therefore, the opening side 3b of the vial 3 is maintained at a relatively low temperature, and as a result, the water contained in the C-11 labeled methyl iodide is cooled by the wall surface of the opening side 3b or the like and easily forms water droplets. Thus, the opening side 3b of the vial 3 partitioned by the bowl-shaped member 21 functions as a cooling means for liquefying the water contained in the C-11 labeled methyl iodide. In addition, in order to exhibit this effect effectively, it is preferable to employ the elongated vial 3, and for example, the length of the vial 3 is preferably 6 times the diameter or more. As described above, since the opening side 3b functions as a cooling means, the above-described cooling pipe or the like can be omitted, and a general-purpose vial 3 having only one end opened can be used. Since a general-purpose vial is relatively inexpensive, it is possible to operate the vial 3 in a disposable manner.

  Further, in the synthesizing apparatus 1, the bottom side 3 a of the vial 3 is inserted from the insertion port 7 of the collar 9, and the collar 21 attached to the vial 3 is supported by the collar 9. With this structure, vials of various diameters can be used as long as the diameter is smaller than that of the insertion port 7, and the range of selection of vials is widened.

  Since the heating device 5 sends hot air to the bottom side 3 a of the vial 3 by the blower 11, the hot air easily flows to the opening side 3 b of the vial 3. For this reason, there is a concern that the temperature of the opening side 3b will rise. However, since the bowl-shaped member 21 blocks the flow of hot air, the function of the bowl-shaped member 21 such as avoiding heating of the opening side 3b is more preferable. Demonstrated.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and may be modified without changing the gist described in each claim.

  DESCRIPTION OF SYMBOLS 1 ... Synthesis | combination apparatus, 3 ... Vial bottle (reaction container), 3a ... Bottom part side, 3b ... Opening side, 9 ... Gutter part (support body), 11 ... Air blower part (heating means), 13 ... Opening, 21 ... Gutter shape Members 31 ... injection needle (raw material gas introduction means), 33 ... injection needle (product acquisition means).

Claims (1)

A bottomed cylindrical reaction vessel having only one opening provided at one end and containing a lithium aluminum hydride solution;
Heating means for heating the bottom of the reaction vessel;
Raw material gas introduction means for blowing C-11 labeled carbon dioxide into the lithium aluminum hydride solution in the reaction vessel through the opening,
C-11-labeled methyl iodide produced in the reaction vessel, product obtaining means for taking out from the reaction vessel through the opening in a gaseous state,
A flanged member attached to the outer wall surface of the counter-reaction container unit,
A support for supporting the bowl-shaped member attached to the reaction vessel in a state where the bottom side of the reaction vessel is inserted from above and the bottom side is inserted into the insertion port; With
The heating means sends hot air to the bottom of the reaction vessel protruding downward from the insertion port,
The apparatus for synthesizing C-11-labeled methyl iodide , wherein the hook-shaped member partitions an upper part and a lower part of the insertion port, and blocks the flow of the hot air above the insertion port .

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