Examination of nature's favorite molecules reveals a striking preference for making carbon-heteroatom bonds over carbon-carbon bonds-surely no surprise given that carbon dioxide is nature's starting material and that most reactions are performed in water. Nucleic acids, proteins, and polysaccharides are condensation polymers of small subunits stitched together by carbon-heteroatom bonds. Even the 35 or so building blocks from which these crucial molecules are made each contain, at most, six contiguous C-C bonds, except for the three aromatic amino acids. Taking our cue from nature's approach, we address here the development of a set of powerful, highly reliable, and selective reactions for the rapid synthesis of useful new compounds and combinatorial libraries through heteroatom links (C-X-C), an approach we call "click chemistry". Click chemistry is at once defined, enabled, and constrained by a handful of nearly perfect "spring-loaded" reactions. The stringent criteria for a process to earn click chemistry status are described along with examples of the molecular frameworks that are easily made using this spartan, but powerful, synthetic strategy.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/1521-3773%2820010601%2940%3A11%3C2004%3A%3AAID-ANIE2004%3E3.0.CO%3B2-5

Click Chemistry: Diverse Chemical Function from a Few Good Reactions.

It has become evident that fluorinated compounds have a remarkable record in medicinal chemistry and will play a continuing role in providing lead compounds for therapeutic applications. This tutorial review provides a sampling of renowned fluorinated drugs and their mode of action with a discussion clarifying the role and impact of fluorine substitution on drug potency.

/pdf/fluorine-in-medicinal-chemistry-4kwoqx8yba.pdf

Fluorine in medicinal chemistry.

Ecotoxicology of human pharmaceuticals.

Cyclooxygenase (COX), first purified in 1976 and cloned in 1988, is the key enzyme in the synthesis of prostaglandins (PGs) from arachidonic acid. In 1991, several laboratories identified a product from a second gene with COX activity and called it COX-2. However, COX-2 was inducible, and the inducing stimuli included pro-inflammatory cytokines and growth factors, implying a role for COX-2 in both inflammation and control of cell growth. The two isoforms of COX are almost identical in structure but have important differences in substrate and inhibitor selectivity and in their intracellular locations. Protective PGs, which preserve the integrity of the stomach lining and maintain normal renal function in a compromised kidney, are synthesized by COX-1. In addition to the induction of COX-2 in inflammatory lesions, it is present constitutively in the brain and spinal cord, where it may be involved in nerve transmission, particularly that for pain and fever. PGs made by COX-2 are also important in ovulation and in the birth process. The discovery of COX-2 has made possible the design of drugs that reduce inflammation without removing the protective PGs in the stomach and kidney made by COX-1. These highly selective COX-2 inhibitors may not only be anti-inflammatory but may also be active in colon cancer and Alzheimer’s disease.

Cyclooxygenases 1 and 2

The Many Roles for Fluorine in Medicinal Chemistry

A series of sulfonamide-containing 1,5-diarylpyrazole derivatives were prepared and evaluated for their ability to block cyclooxygenase-2 (COX-2) in vitro and in vivo. Extensive structure-activity relationship (SAR) work was carried out within this series, and a number of potent and selective inhibitors of COX-2 were identified. Since an early structural lead (1f, SC-236) exhibited an unacceptably long plasma half-life, a number of pyrazole analogs containing potential metabolic sites were evaluated further in vivo in an effort to identify compounds with acceptable pharmacokinetic profiles. This work led to the identification of 1i (4-[5-(4-methylphenyl)-3-(trifluoromethyl)- H-pyrazol-1-yl]benzenesulfonamide, SC-58635, celecoxib), which is currently in phase III clinical trials for the treatment of rheumatoid arthritis and osteoarthritis.

Synthesis and biological evaluation of the 1,5-diarylpyrazole class of cyclooxygenase-2 inhibitors: identification of 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benze nesulfonamide (SC-58635, celecoxib).

A class of pyrazolyl benzenesulfonamide compounds is described for use in treating inflammation and inflammation-related disorders. Compounds of particular interest are defined by formula (II), whrein R2 is selected from hydrido, alkyl, haloalkyl, alkoxycarbonyl, cyano, cyanoalkyl, carboxyl, aminocarbonyl, alkylaminocarbonyl, cycloalkylaminocarbonyl, arylaminocarbonyl, carboxyalkylaminocarbonyl, carboxyalkyl, aralkoxycarbonylalkylaminocarbonyl, aminocarbonylalkyl, alkoxycarbonylcyanoalkenyl and hydroxyalkyl; wherein R3 is selected from hydrido, alkyl, cyano, hydroxyalkyl, cycloalkyl, alkylsulfonyl and halo; and wherein R4 is selected from aralkenyl, aryl, cycloalkyl, cycloalkenyl and heterocyclic; wherein R4 is optionally substituted at a substitutable position with one or more radicals selected from halo, alkylthio, alkylsulfonyl, cyano, nitro, haloalkyl, alkyl, hydroxyl, alkenyl, hydroxyalkyl, carboxyl, cycloalkyl, alkylamino, dialkylamino, alkoxycarbonyl, aminocarbonyl, alkoxy, haloalkoxy, sulfamyl, heterocyclic and amino; provided R?2 and R3? are not both hydrido; further provided that R2 is not carboxyl or methyl when R3 is hydrido and when R4 is phenyl; further provided that R4 is not triazolyl when R2 is methyl; further provided that R4 is not aralkenyl when R2 is carboxyl, aminocarbonyl or ethoxycarbonyl; further provided that R4 is not phenyl when R2 is methyl and R3 is carboxyl; and further provided that R4 is not unsubstituted thienyl when R2 is trifluoromethyl; or a pharmaceutically acceptable salt thereof.

Substituted pyrazolyl benzenesulfonamides for the treatment of inflammation

Improved Procedure for the Reduction of N-Acyloxazolidinones

A class of 1,3,5-substituted pyrazoles is described for the treatment of inflammation, including treatment of pain and disorders such as arthritis. Compounds of particular interest are of formula (I) wherein R1 is lower alkylsulfonyl or sulfamyl; wherein R2 is aryl or heteroaryl; wherein R2 is optionally substituted at a substitutable position with one or more radicals selected from halo, lower alkoxy, lower alkyl, nitro, lower alkylthio, amino, lower haloalkyl, hydroxyl, carboxyl, N-monoalkylamino, N,N-dialkylamino, cyano, alkoxycarbonyl and acylamino; wherein R3 is selected from hydrido, lower alkyl, lower haloalkyl, cyano, carboxyl, alkoxycarbonyl, amino, acyl, acylamino, halo and alkylsulfonylamino; wherein R4 is aryl or heteroaryl; wherein R4 is optionally substituted at a substitutable postion with one or more radicals selected from halo, lower alkoxy, lower alkyl, nitro, lower alkylthio, amino, lower haloalkyl, hydroxyl, carboxyl, N-monoalkylamino, N,N-dialkylamino, cyano, alkoxycarbonyl and acylamino; provided at least one or R?2 and R4? cannot be phenyl or substituted triazole, when R1 is sulfamyl; further provided R2 cannot be 4-methoxyphenyl or 4-methylphenyl when R4 is 4-methoxyphenyl or 4-methylphenyl, and when R1 is sulfamyl; and further provided that R2 cannot be tetrazole when R4 is fluorophenyl, and when R1 is methylsulfonyl; or a pharmaceutically-acceptable salt thereof.

1,3,5 trisubstituted pyrazole compounds for treatment of inflammation

This invention encompasses compounds of Formula 1 and the pharmaceutically acceptable salts thereof.
 wherein 
    R¹ represents alkyl having 2-6 carbon atoms; 
    R² represents methyl or ethyl; 
    R³ represents alkyl having 1 to 5 carbon atoms; 
    W represents (CH₂) x where x is 2 to 7, alkylene having 2 to 7 carbon atoms, alkenylene having 3 to 7 carbon atoms, alkynylene having 3 to 7 carbon atoms, or cyclopentyl; 
    R⁴ represents hydrogen, alkyl having 2-5 carbon atoms, alkenyl having 2 to 5 carbon atoms, or alkynyl having 2 to 5 carbon atoms; 
    Q represents oxygen or CH₂; 
    B represents CH₂, C=O or CH-OH; 
    R⁵ represents hydrogen, alkyl having 1 to 6 carbon atoms, or R⁵ and R⁶ together optionally represent a carbon to carbon bond; or R⁵ represents alkanoyl having 2 to 4 carbon atoms, carboxy, alkoxycarbonyl, or (CH₂)y-CO₂R⁸ wherein y is 0 to 4 and R⁸ is hydrogen or alkyl having 1 to 6 carbon atoms; and     A represents -Z-CO₂R⁷ or -Z-COR⁹R¹⁰ wherein R⁷ represents hydrogen or alkyl having 1 to 6 carbon atoms, R⁹, R¹⁰, represent hydrogen, alkyl having 1 to 6 carbon atoms, or cycloalkyl having 3 to 6 carbon atoms or NR⁹R¹⁰ form a heterocyclic ring, and wherein Z is absent or represents straight or branched chain alkylene or alkenylene having up to 6 carbon atoms. These compounds are selective antagonists of leukotriene B₄(LTB₄) with little or no antagonism of leukotriene D₄ (LTD₄) and are useful anti-inflammatory agents for treating inflammatory bowel disease, rheumatoid arthritis, gout and psoriasis.

Stella S. Yu

Papers

Synthesis and biological evaluation of the 1,5-diarylpyrazole class of cyclooxygenase-2 inhibitors: identification of 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benze nesulfonamide (SC-58635, celecoxib).

Substituted pyrazolyl benzenesulfonamides for the treatment of inflammation

Improved Procedure for the Reduction of N-Acyloxazolidinones

1,3,5 trisubstituted pyrazole compounds for treatment of inflammation

Alkoxy-substituted dihydrobenzopyran-2-carboxylate derivatives