JPH0680082B2 - Aromatic carbamate derivatives of polysaccharides - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel aromatic carbamate derivative of polysaccharide. More specifically, the present invention provides an aromatic carbamate derivative of an optically active polysaccharide having an aromatic azo group.

[Conventional technology and problems]

Aromatic azo compounds, such as azobenzene [I], emit light (h
ν) or heat (△), as shown in the following equation, −N =
It is known that cis-trans isomerization occurs reversibly with respect to the N-2 double bond.

On the other hand, the present inventors have conducted research on a polysaccharide phenylcarbamate that can be used as a separating agent, and as a result of various studies on compounds capable of imparting new separating characteristics, they have found a novel compound of the present invention. It is an ivy.

[Means for solving problems]

That is, the present invention relates to an aromatic carbamate derivative of an optically active polysaccharide selected from cellulose tris (4-phenylazophenyl carbamate) or amylose tris (4-phenylazophenyl carbamate).

The compound of the present invention reacts with a polysaccharide residue by reacting a polysaccharide with an aromatic azo compound having an isocyanate group. It can be obtained by binding an azo compound via a bond. That is, it binds to all of OH, which is a functional group of the polysaccharide, Is formed (R is However, it may have a substituent on the benzene ring). The aromatic azo compound having an isocyanate group can be easily obtained, for example, by reacting phosgene with the amino group of the corresponding aromatic azo compound.

Since the aromatic carbamate derivative of the polysaccharide of the present invention is an optically active saccharide to which an azo compound which causes cis-trans isomerization by light or heat as described above is bound, it is a filler for optical resolution. Is expected to be used.
Furthermore, it is expected that the separation characteristics will be varied due to the action of light or heat. Further, the polysaccharide derivative having an aromatic azo group of the present invention undergoes cis-trans isomerization even if the film obtained by casting the THF solution on a quartz plate and then drying it under light shielding is irradiated with light. . Therefore, application as a separation membrane is also expected.

〔Example〕

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

In addition, the measurement of the spectrum in the examples was performed using the following apparatus.

IR spectrum: JASCO.IR-810 Infrared Spectroscopy. CD spectrum: JASCO-J-40 Spectropolarimeter Optical polarimeter: JASCO, DIP-181 Digital Polarimeter Example-1 [Synthesis of cellulose tris (4-phenylazophenylcarbamate)] (1) Synthesis of 4-phenylazophenyl isocyanate Approximately 200 ml of toluene is placed in a flask and phosgene is fed into toluene while stirring. A solution of 21.65 g of p-aminoazobenzene in toluene (300 ml) was added dropwise to the place where the flask was replaced with phosgene to cause a reaction. The reaction flask was gradually heated, and the temperature was raised from room temperature to about 120 ° C., and the reaction was carried out under reflux of toluene. Phosgene was expelled from the flask, the reaction solution was heated in an oil bath under normal pressure, and toluene was distilled off. Yield 39.6g (but containing a small amount of toluene) IR spectrum (No.562) -N = C = O: 2250cm ^-1 (2) Synthesis of cellulose tris (4-phenylazophenylcarbamate) 0.400g cellulose 20 ml of pyridine and 6.78 g of 4-phenylazophenyl isocyanate synthesized in (1) above.
The mixture (weight including toluene) was reacted at about 105 ° C. for 20 hours. The reaction solution was poured into 300 ml of methanol to precipitate the product. The precipitate was collected with a glass filter, washed with methanol, and then dried under reduced pressure in a desiccator.
It was vacuum dried at 60 ° C. for 2 hours. The product was a mixture of disubstituted urea and carbamate, and the yield was 2.60 g. As a result of dissolving 2.51 g of this mixture in 25 ml of ethyl acetate and separating the solvent, disubstituted urea was obtained as an insoluble portion and carbamate was obtained as a soluble portion. Both were separated by centrifugation, and the soluble part was poured into methanol to precipitate the carbamate.
The precipitate was collected again with a glass filter, washed with methanol, dried under reduced pressure in a desiccator, and further vacuum dried at 60 ° C. for 2 hours. Yield 1.81 g, 91%, the product is presumed to be a compound in which all the OH groups of the cellulose represented by the following formula are replaced by 4-phenylazofuel carbamate groups. Confirmed by analysis.

IR spectrum. (No.601) Carbamate C ＝ O: 1730cm
^-1 Elemental analysis value, Measurement value: C, 64.96%; H, 4.50%; N, 14.95% Calculated value: C, 64.97%; H, 4.48%; N, 15.16% Example 2 [Cis-trans isomerization of cellulose tris (4-phenylazophenyl carbamate)] (1) Isomerization by light Tetrahydrofuran (THF) solution of trans-form cellulose tris (4-phenylazophenyl carbamate) was made into quartz. It was placed in a cell and irradiated with light from a 300 W high-pressure mercury lamp. The wavelength of light is UV-D36C and UV, a filter made by Toshiba Glass.
It was adjusted to 400 nm> λ ₁ > 340 nm by -35. This light isomerized the trans form to the cis form. Also,
Isomerization from the cis form to the trans form was carried out by the light passing through the filter Y-47. All the light irradiation was performed at room temperature, and the solution had a concentration of about 0.1 to 0.2 mg / ml. The change in visible-ultraviolet absorption spectrum due to each isomerization was measured. The results are shown in Figures 1 and 2.

(2) Isomerization by heat Put THF solution of trans-form into quartz cell and 400nm> λ ₁ > 34
It was isomerized to a cis form by 0 nm light. The cell was placed in a constant temperature water bath at 25 ° C., shielded from light, and the visible-ultraviolet absorption spectrum at each elapsed time was measured to examine the change accompanying isomerization and the rate of isomerization. The results are shown in Figure 3.

Example 3 (Change in CD spectrum due to isomerization) A THF solution of trans isomer was put in a quartz cell of 1 mm or 1 cm to isomerize it to a cis isomer by light of 400 nm> λ ₁ > 340 nm. The absorption spectrum and the CD spectrum of the trans form, the cis form, and those containing both were measured. In addition, the cis isomer was once converted into the trans isomer by light having a wavelength of λ ₂ > 470 nm. The measurement of the CD spectrum uses a 1 cm cell for 600-400 nm, 400-210 n
m was measured using a 1 mm cell. Solution concentration is 0.178m
It was done in g / ml. The results are shown in Figure 4.

Application Example 1 (Application to filler for optical resolution) i) Preparation of column for optical resolution Dissolve the trans form (750 mg) of cellulose tris (4-phenylazophenylcarbamate) in THF (10 ml),
It was coated on 3-aminopropyltriethoxysilane treated silica gel (3 g). The weight ratio of supported polymer to silica gel is about 25%. The silica gel used was Li Chrospher SI-4000 from Merck; particle size 10μ.
m, pore size 4000 Å, surface area 6 m ² / g. The prepared packing material was packed in a 25 cm × 0.46 (id) cm stainless steel column by a slurry packing method.

ii) The results of fractionation for various racemic compounds are shown in Table 1 below.

Example 4 (Synthesis of amylose tris (4-phenylazophenyl carbamate)) Amylose was synthesized by reacting excess 4-phenylazophenyl isocyanate in pyridine at about 100-110 ° C.
Purification and confirmation of the product were carried out in the same manner as in the case of cellulose.

Elemental analysis value Measured value: C, 64.89; H, 4.46; N, 15.21% Calculated value: C, 64.97; H, 4.48; N, 15.16%

[Brief description of drawings]

1 to 3 are diagrams of visible-ultraviolet absorption spectrum of the compound of the present invention, and FIG. 4 is a diagram of CD spectrum.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G01N 30/48 W 8310-2J

Claims (1)

[Claims] 1. A polysaccharide aromatic carbamate derivative selected from cellulose tris (4-phenylazophenyl carbamate) or amylose tris (4-phenylazophenyl carbamate).