CS252998B1 - O- (3-Dimethylamino-2-hydruxypropyl) cellulose and its preparation - Google Patents

Abstract

The solution relates to a new cellulose derivative, which is prepared by reacting O-(3-chloro-2-hydroxypropyl)cellulose with an aqueous solution of dimethylamine at room temperature for 4 to 8 hours, and then the prepared O-(3-dimethylamino-2-hydroxypropyl)cellulose is isolated from the reaction mixture. The substance prepared according to the invention has applications in the preparation of moderately basic anions and in organic synthesis in preparation of benzoylated and benzylated cellulose esters O-benzoyl-(O--3-dimethylamino-2-hydroxypropyl)cellulose, O-benzyl-(3-dimethylamino-2-hydroxypropyl)cellulose.

Description

The invention relates to O- (3-dimethylamino-2-hydroxypropyl) cellulose and to a process for its preparation.

The preparation of O- (3-dimethylamino-2-hydroxypropyl) cellulose is not known from the literature.

The present invention provides O- (3-dimethylamino-2-hydroxypropyl) cellulose and a process for the preparation thereof by reacting O- (3-chloro-2-hydroxypropyl) cellulose with an aqueous dimethylamine solution at room temperature for a period of time. 4-8 hours and then the prepared O- (3-dimethylamino-2-hydroxypropyl) cellulose is isolated from the reaction mixture.

The finished product should have a nitrogen content of 1 to 1.5% by weight. The new cellulose derivative can be used after esterification e.g. benzoyl chloride to replace benzoylated diethylaminoethylcellulose in the separation of cereal proteins in column chromatography.

The advantage of the proposed process for the preparation of O- (3-dimethylamino-2-hydroxypropyl) cellulose is that it expands the range of this group of cellulose ethers with a new derivative.

Further advantages of the present process are the applicability to any type of cellulose (spherical, fibrous and powdered materials), simplicity, and the fact that the reaction does not crosslink the parallel cellulose chains by cross-linking 2-hydroxytrimethylene bonds. Hydroxypropyl cellulose is a readily available cellulose derivative L. Petruš, P. Gemeiner: Chem. Annals 38, 133 (1984).

O- (3-dimethylamino-2-hydroxypropyl) cellulose has the properties of a weak base anion exchanger; flow, swelling volume reactivity and the like.

Example 1

Mixture of aspirated spherical O- (3-chloro-2-hydroxypropyl) cellulose 5.5 g, dry matter 18.1% w / w. Chlorine content 4.13 wt. and 25 wt. of an aqueous solution of dimethylamine (10 mL) was reacted with stirring at room temperature for 4 hours. After the reaction, the solid phase was filtered off, washed with water (5 X 50 ml), 0.5 mol. 1 ^-1 aqueous sodium hydroxide solution (3 X 20 mL) and finally water to neutralize the filtrate. White spherical O- (3-dimethylamino-2-hydroxypropyl) cellulose (4.9 g, 16.4 wt% dry matter, 1.02 wt% nitrogen, 0.0 wt% chlorine) was obtained.

Example 2

A mixture of O- (3-chloro-2-hydroxypropyl) cellulose (7.4 g, 4.31% by weight of chlorine, prepared from the starting microcrystalline cellulose) and 20 ml of 25% by weight of cellulose. of an aqueous dimethylamine solution was reacted with stirring at room temperature for 8 hours. The procedure was as in Example 1 except that the solid phase was finally washed with methanol (3 X 20 ml) and dried from ether. White O- (3-dimethylamino-2-hydroxypropyl) cellulose (6.9 g, 1.32 wt% nitrogen, 0.0 wt% chlorine) was obtained.

Example 3

Mixture of O- (3-chloro-2-hydroxypropyl) cellulose (0.5 g, 5.7% by weight of chlorine prepared from starting beech kraft cellulose) and 50% by weight of cellulose. aqueous dimethylamine solution (4 mL) was reacted with stirring at room temperature for 6 hours. The white O- (3-dimethylamino-2-hydroxypropyl) cellulose (0.5 g, 1.48% nitrogen, 0.0% chlorine) dissolved in cadoxene was obtained.

The invention is of importance in the preparation of intermediate basic anion exchangers and in organic synthesis in the preparation of benzoylated and benzylated cellulose esters [O-benzoyl- (O-3-dimethylamino-2-hydroxypropyl) cellulose, O-benzyl- (O-3-dimethylamino-2-hydroxypropyl) (cellulose).

Claims (2)

PREDMET 1. O- (3-dimethylamino-2-hydroxypropyl) cellulose, R-O-CH 2 CH (OH) CH 2 N (CH 3) 2, wherein R is cellulose. 2. A process for preparing O- (3-dimethylamino-2-naphthalene-hydroxypropyl) cellulose according to claim 1, wherein the O- (3-chloro-2-hydroxypropyl) cellulose is reacted with an aqueous solution of dimethylamine at room temperature for 4 hours. for up to 8 hours and then isolating the product from the reaction mixture.