New synthesis method of important biochemical reagent L-leucine-4-nitroaniline hydrochloride

Abstract

The invention relates to a new synthesis method of an important biochemical reagent L-leucine-4-nitroaniline hydrochloride. The method includes: under the action of sodium hydroxide, reacting an L-Leu-OH solution with BOC anhydride to obtain Boc-L-Leu-OH; subjecting the Boc-L-Leu-OH and a pyridine solution of p-nitroaniline to condensation under the action of phosphorus oxychloride so as to generate the key intermediate Boc-L-Leu-pNA, with the condensation method being novel and not reported in the literature; and reacting a glacial acetic acid solution of the Boc-L-Leu-pNA with a hydrogen chloride gas so as to generate Boc-L-leucine-4-nitroaniline hydrochloride. The method has the advantages of easily available starting raw materials, short reaction steps, convenient operation, high yield, and low cost.

Description

technical field [0001] The invention belongs to the field of biochemical reagent amino acid p-nitroaniline, in particular to a new method for synthesizing fluorescent peptidase substrates. Background technique: [0002] The amino acid p-nitroaniline is a valuable and widely used chromogenic substrate for the determination of proteolytic enzyme activity in body fluids; L-leucine-4-nitroaniline is a substrate for leucine aminopeptidase; In addition, L-leucine-4-nitroaniline hydrochloride can also be used as an intermediate of diazo dyes and sulfur dyes (such as oxaprop-methyl, fluorescent whitening agent KCB). However, since p-nitroaniline is a very weak nucleophile, the synthesis of such compounds is very difficult and the yield is very low. [0003] [0004] But now it is known that there are many methods for preparing the key intermediate Boc-L-leucine-4-nitroaniline (Boc-L-Leu-pNA). Condensation reagents such as DCC, DCC / HOBt, or the anhydride method carry out direct ...

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Problems solved by technology

[0004] But now it is known that there are many methods for preparing the key intermediate Boc-L-leucine-4-nitroaniline (Boc-L-Leu-pNA). Condensation reagents such as DCC, DCC / HOBt, or acid anhydride method for direct condensation yields are very low (0-30%)

Document 1: (Shioiri, Takayuki; Murata, Mitsuo; Hamada, Yasumasa; Chemical and Pharmaceutical Bulletin; 1987; 35(7); 2698-2704) used a series of improved condensation methods, but the effect is still unsatisfactory. This method of literature adopts multiple methods and condensing agents, and there are results such as non-reaction or very low yield, and highly toxic reagents (such as ethyl chloroformate) are used. In addition, the chemical reagents used for synthesis are very expensive and the cost is relatively high (see table 1)

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