# New Pyrimidine Chemical Compounds for Treating Tumors

> This patent describes specific new chemical compounds, called N-phenyl-2-pyrimidine-amine derivatives, designed with precise molecular structures for potential use in treating cancer.

- **Patent:** US 5521184
- **Original title:** Pyrimidine derivatives and processes for the preparation thereof
- **Owner:** Ciba Geigy Corp
- **Granted:** 1996
- **Status:** Public domain (expired)
- **Times cited:** 564
- **Field:** pharmaceutical, biotech, chemistry, oncology

## What it does

This patent claims a specific group of N-phenyl-2-pyrimidine-amine chemical compounds, identified by a general chemical structure called Formula I. The claims precisely define various parts of this molecule, known as 'R' groups (R1 through R10), along with X, Y, and n. For example, R1 can be 4-pyrazinyl or 1-methyl-1H-pyrrolyl, and R2 and R3 are hydrogen or lower alkyl. Crucially, one or two of the R4-R8 positions must include a nitro group, a fluoro-substituted lower alkoxy group, or a specific radical of Formula II, which itself has detailed definitions for R9, X, Y, n, and R10. The patent abstract states these compounds can be used in the therapy of tumoral diseases. An example compound would have R1 as 4-pyrazinyl, R2 and R3 as hydrogen, and one of R4-R8 as a radical of Formula II where R10 is an aliphatic radical with at least 5 carbon atoms.

## What it does NOT cover

- Does not cover pyrimidine derivatives that do not match the exact N-phenyl-2-pyrimidine-amine core structure of Formula I.
- Does not cover compounds where the R1 substituent is not one of the specifically listed groups, such as 4-pyrazinyl or 1-methyl-1H-pyrrolyl.
- Does not cover compounds where the R10 radical in Formula II has fewer than 5 carbon atoms if it is an aliphatic radical.
- Does not cover compounds where the R4-R8 substituents do not include at least one of the specified nitro, fluoro-substituted lower alkoxy, or Formula II radicals.
- Does not cover compounds where the R10 radical is an aromatic-aliphatic radical but the phenyl portion is substituted differently than described in claim 3.

## The clever bit

The novelty lies in the specific combination of chemical groups attached to the N-phenyl-2-pyrimidine-amine core, particularly the detailed definitions for R1 and the specific requirements for at least one of the R4-R8 positions, which together yield compounds with therapeutic potential for tumors.

## Real-world examples

1. Imatinib (Gleevec) - a pyrimidine derivative developed by Novartis for treating certain cancers.
2. Other tyrosine kinase inhibitors used in oncology.
3. Early-stage drug candidates targeting specific tumor pathways.

## Why it matters

This patent is foundational in pharmaceutical chemistry, defining a class of compounds with potential anti-tumor activity. It represents early work by Ciba Geigy, a company that later became part of Novartis, a major player in oncology. Such patents are critical for establishing intellectual property around new drug candidates, guiding further research and development in cancer treatment.

## Frequently asked questions

### What does New Pyrimidine Chemical Compounds for Treating Tumors cover?

This patent describes specific new chemical compounds, called N-phenyl-2-pyrimidine-amine derivatives, designed with precise molecular structures for potential use in treating cancer.

### Who owns patent US 5521184?

Ciba Geigy Corp owns this patent, granted in 1996.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 5521184 cited by?

This patent has been cited by 564 later patents that build on its ideas.

### What problem does this patent solve?

This patent is foundational in pharmaceutical chemistry, defining a class of compounds with potential anti-tumor activity. It represents early work by Ciba Geigy, a company that later became part of Novartis, a major player in oncology. Such patents are critical for establishing intellectual property around new drug candidates, guiding further research and development in cancer treatment.

### What does this patent NOT cover?

Does not cover pyrimidine derivatives that do not match the exact N-phenyl-2-pyrimidine-amine core structure of Formula I.

**Full plain-English explainer:** https://patentbrief.org/patent/us/5521184/gleevec-imatinib

**Original patent:** https://patents.google.com/patent/US5521184

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._