2-Amino-3,5-dibromopyrazine CAS 24241-18-7

1. Pyrazine Nucleus: As an electron deficient aromatic heterocyclic ring, it has good biocompatibility and metabolic stability. It can simulate the adenine structure in ATP molecules and form specific hydrogen bonds with the kinase hinge region in tumor cells. This is the core structural basis for its derivatives to have anti-tumor activity and is also the key to adapting to the binding requirements of anti-tumor drug targets such as kinase inhibitors and DNA topoisomerase inhibitors; Meanwhile, the aromaticity of pyrazine ring makes its derivatives difficult to be rapidly metabolized and degraded in vivo, prolonging the drug's action time and enhancing anti-tumor efficacy.

2. 3,5-dibromo atom: As a strong leaving group, it has extremely high reactivity and can accurately undergo single substitution, double substitution, or cross coupling reactions. It efficiently introduces anti-tumor pharmacophores such as aryl, amino, alkoxy, and heterocyclic groups, and optimizes the anti-tumor activity and pharmacokinetic properties of derivatives by regulating their lipid solubility, water solubility, and target affinity; In addition, the strong electron withdrawing effect of bromine atoms can regulate the electron cloud density of pyrazine rings, enhance the binding ability of derivatives with tumor targets, and improve targeting.

3. 2-Amino: Strong nucleophilicity, can undergo various derivatization reactions such as acylation, alkylation, condensation, diazotization, cyclization, etc., used to connect different pharmacophores (such as morpholine ring, piperazine ring, aromatic ring), form hydrogen bonds or electrostatic interactions, further enhancing the binding specificity of derivatives with tumor targets; Meanwhile, amino groups can improve the water solubility of derivatives, reduce the toxic side effects of drugs, and enhance their bioavailability in vivo.

In addition, the symmetrical double bromine substitution structure of the compound makes its derivatization reaction highly selective, and precise control of single or double bromine substitution can be achieved by controlling reaction conditions (such as catalyst, temperature, reaction time), avoiding excessive by-products and reducing the purification difficulty of anti-tumor drug synthesis, making it suitable for industrial large-scale production.

Cross coupling reaction (accounting for over 70% of anti-tumor drug synthesis reactions): This is the most core reaction type of 2-AMINO-3,5-DIBROMOPYRAZIN, which mainly couples with different substrates through 3,5-dibromo sites, constructs C-C and C-N bonds, and introduces anti-tumor pharmacophores. Among them, the Suzuki Miyaura coupling reaction is the most widely used, which can react with arylboronic acid, introduce aryl groups, enhance the lipid solubility and target affinity of derivatives, and is used for the synthesis of imidazole pyrazine and bipyrazine anti-tumor derivatives;

The Buchwald Hartwig amination reaction can react with amine compounds such as piperazine and morpholine, introduce amino heterocycles, optimize the water solubility and biological activity of derivatives, and be used for the synthesis of kinase inhibitor anti-tumor drugs; The Heck coupling reaction can react with olefin compounds to construct unsaturated bonds, regulate the spatial structure of molecules, and enhance the anti-tumor activity of derivatives.

Ring reaction (key to the construction of fused ring anti-tumor drugs): 2-AMINO-3,5-DIBROMOPYRAZIN can undergo condensation ring reaction with isothiocyanates, thiourea, o-phenylenediamine, α - halogenated ketones and other compounds through the pyrazine nucleus to construct fused ring heterocyclic structures such as imidazopyrazine, thiazole pyrazine, quinoxaline, etc. The condensed ring structure can significantly enhance the conjugated system of derivatives, improve their binding ability with tumor targets, and enhance the metabolic stability of molecules, which is the core skeleton of highly active anti-tumor drugs; For example, thiazole pyrazine derivatives formed by cyclization with isothiocyanates have significant anti liver cancer and lung cancer activity.

3. Amino derivatization reaction (pharmacophore modification and optimization): 2-Amino can undergo acylation, alkylation, and condensation reactions with carboxylic acids, anhydrides, halogenated alkanes, aldehydes, ketones, and other compounds to generate amide, N-alkylamine, Schiff base, and other derivatives, which are used to regulate the lipid water distribution coefficient, metabolic stability, and target selectivity of drug molecules.

For example, aminoacylation modification can reduce the toxicity of derivatives and enhance their bioavailability in vivo; Aminoalkylation modification can introduce hydrophilic groups, improve the water solubility of drugs, and facilitate in vivo absorption.
In addition, the compound can also undergo nucleophilic substitution reactions, introducing functional groups such as hydroxyl and alkoxy through single or double bromine substitution, further enriching the structural diversity of anti-tumor derivatives and meeting the research and development needs of different tumor targets.

Bromine atom: 3,5-dibromo substitution is an important condition for derivatives to possess high anti-tumor activity; The activity of single bromine substituted derivatives is only 30% -50% of that of double bromine substituted derivatives, while non bromine substituted derivatives have almost no anti-tumor activity; Meanwhile, the substitution position of the bromine atom cannot be changed. If the bromine atom is substituted at other positions of the pyrazine ring (such as positions 2 and 4), it will cause changes in the spatial structure of the derivative, making it unable to bind to tumor targets and lose its activity.

Amino group: The 2-position amino group is a key site for pharmacophore linkage. If the amino group is substituted or removed, the anti-tumor activity of the derivative will be significantly reduced; The type of substituent on the amino group directly affects the activity - introducing heterocyclic substituents such as morpholine ring and piperazine ring can enhance the water solubility and target affinity of derivatives, and improve anti-tumor activity; Introducing aryl substituents can enhance lipid solubility and prolong drug action time; Introducing acyl substituents can reduce toxicity and enhance bioavailability.

Conjugated system: The longer the conjugated system of the derivative, the stronger its anti-tumor activity; By constructing fused ring structures through cyclization reactions or introducing aromatic or heterocyclic groups through coupling reactions, the conjugated system can be extended, enhancing the binding ability of molecules to tumor targets and improving anti-tumor activity.