Application of the Dakin-West reaction for the synthesis of oxazole-containing dual PPARalpha/gamma agonists

Oxazole and thiazole analogs of sulindac for cancer prevention

Aim:

Experimental and epidemiological studies and clinical trials suggest that nonsteroidal anti-inflammatory drugs possess antitumor potential. Sulindac, a widely used nonsteroidal anti-inflammatory drug, can prevent adenomatous colorectal polyps and colon cancer, especially in patients with familial adenomatous polyposis. Sulindac sulfide amide (SSA) is an amide-linked sulindac sulfide analog that showed in vivo antitumor activity in a human colon tumor xenograft model.

Results/methodology:

A new analog series with heterocyclic rings such as oxazole or thiazole at the C-2 position of sulindac was prepared and screened against prostate, colon and breast cancer cell lines to probe the effect of these novel substitutions on the activity of sulindac analogs.

Conclusion:

In general, replacement of the amide function of SSA analogs had a negative impact on the cell lines tested. A small number of hits incorporating rigid oxazole or thiazole groups in the sulindac scaffold in place of the amide linkage show comparable activity to our lead agent SSA.

Synthesis and antifungal activity of bile acid-derived oxazoles

Peracetylated bile acids (1a-g) were used as starting materials for the preparation of fourteen new derivatives bearing an oxazole moiety in their side chain (6a-g, 8a-g). The key step for the synthetic path was a Dakin-West reaction followed by a Robinson-Gabriel cyclodehydration. A simpler model oxazole (12) was also synthesized. The antifungal activity of the new compounds (6a-g) as well as their starting bile acids (1a-g) was tested against Candida albicans. Compounds 6e and 6g showed the highest percentages of inhibition (63.84% and 61.40% at 250 μg/mL respectively). Deacetylation of compounds 6a-g, led to compounds 8a-g which showed lower activities than the acetylated derivatives.

Catalytic transformation of esters of 1,2-azido alcohols into α-amido ketones

The esters of 1,2-azido alcohols were transformed into α-amido ketones without external oxidants through the Ru-catalyzed formation of N–H imines with the liberation of N₂ followed by intramolecular migration of the acyl moiety.

Synthesis of N-[aryl(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methyl] Thioacetamide Derivatives

A three-component reaction between 4-hydroxy-6-methyl-2H-pyran-2-one, an aryl aldehyde and thioacetamide catalysed by p-toluenesulfonic acid under reflux conditions provided a simple and efficient one-pot route for the synthesis of N-[aryl(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)methyl]thioacetamide derivatives in excellent yields.

Synthesis of 3-[(acetylamino)(aryl)Methyl]-4-Hydroxy-6-Methyl-2H-Pyran-2-Ones

A one-pot, three-component reaction between aryl aldehydes, 4-hydroxy-6-methyl-2H-pyran-2-one, and acetonitrile in the presence of chlorosulfonic acid affords 3-[(acetylamino)(aryl)methyl]-4-hydroxy-6-methyl-2H-pyran-2-ones in excellent yields.

Crystal structure of 4-tert-butyl-2-{2-[N-(3,3-dimethyl-2-oxobut-yl)-N-iso-propyl-carbamo-yl]phen-yl}-1-isopropyl-1H-imidazol-3-ium perchlorate

In the title salt, C26H40N3O2 (+)·ClO4 (-), the positive charge of the organic cation is delocalized between the two N atoms of the imidazole ring. The C N bond distances are 1.338 (2) and 1.327 (3) Å. The substituents on the benzene ring are rotated almost orthogonal with respect to this ring due to the presence of the bulky isopropyl substituents. The dihedral angle between the benzene and imidazole rings is 75.15 (12)°. Three of the O atoms of the anion are disordered over two sets of sites due to rotation around one of the O-Cl bonds. The ratio of the refined occupancies is 0.591 (14):0.409 (14). In the crystal, the cation and perchlorate anion are bound by an N-H⋯O hydrogen bond. In addition, the cation-anion pairs are linked into layers parallel to (001) by multiple weak C-H⋯O hydrogen bonds.

Synergic effect of nano-catalyst and continuous flow system: Dakin–West reaction catalyzed by Nafion-H@SPIONs in a microreactor

The expansion of practical processes for superferromagnetic nanocatalysts is a very attractive subject.

Synthesis and evaluation of 3-amino/guanidine substituted phenyl oxazoles as a novel class of LSD1 inhibitors with anti-proliferative properties

A series of functionalized phenyl oxazole derivatives was designed, synthesized and screened in vitro for their activities against LSD1 and for effects on viability of cervical and breast cancer cells, and in vivo for effects using zebrafish embryos. These compounds are likely to act via multiple epigenetic mechanisms specific to cancer cells including LSD1 inhibition.

A Three-Component Novel Synthesis of 1-[Aryl(Thioacetamido)Methyl]-2-Naphthol Derivatives

A three-component reaction between 2-naphthol, an aryl aldehydes and thioacetamide catalysed by p-toluenesulfonic acid under reflux conditions provided a simple and efficient one-pot route for the synthesis of 1-[aryl(thioacetamido)methyl]-2-naphthol derivatives in excellent yields.

One-pot synthesis of β-amido ketones using Brønsted acidic ionic liquid as an efficient and reusable catalyst

An efficient protocol was developed for one-pot condensation of an aldehyde, ketone, acetyl chloride, and nitriles catalyzed by a stable and reusable 1-methyl-imidazolium hydrogen sulfate ([Hmim][HSO4]) as a Brønsted acidic ionic liquid. The system tolerated a variety of functional groups affording the corresponding β-amido ketones in moderate to good yields under milder operating conditions.