Oxazole is the parent compound for a vast class of heterocyclic

Heterocyclic compound

A heterocyclic compound is a cyclic compound which has atoms of at least two different elements as members of its ring. The counterparts of heterocyclic compounds are homocyclic compounds, the rings of which are made of a single element....

 aromatic organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

s. These are azole

Azole

An azole is a class of five-membered nitrogen heterocyclic ring compounds containing at least one other non-carbon atom of either nitrogen, sulfur, or oxygen. The parent compounds are aromatic and have two double bonds; there are successively reduced analogs with fewer...

s with an oxygen and a nitrogen separated by one carbon. Oxazoles are aromatic compounds but less so than the thiazoles. Oxazole is a weak base; its conjugate acid

Conjugate acid

Within the Brønsted–Lowry acid-base theory , a conjugate acid is the acid member, HX, of a pair of two compounds that transform into each other by gain or loss of a proton. A conjugate acid can also be seen as the chemical substance that releases, or donates, a proton in the forward chemical...

 has a pKa

PKA

PKA, pKa, or other similar variations may stand for:* pKa, the symbol for the acid dissociation constant at logarithmic scale* Protein kinase A, a class of cAMP-dependent enzymes* Pi Kappa Alpha, the North-American social fraternity...

 of 0.8, compared to 7 for imidazole

Imidazole

Imidazole is an organic compound with the formula C3H4N2. This aromatic heterocyclic is a diazole and is classified as an alkaloid. Imidazole refers to the parent compound, whereas imidazoles are a class of heterocycles with similar ring structure, but varying substituents...

.
Classical oxazole synthetic methods in organic chemistry

Organic chemistry

Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...

 are

• the Robinson-Gabriel synthesis
  Robinson-Gabriel synthesis
  The Robinson-Gabriel synthesis is a chemical reaction that forms oxazoles by dehydration of 2-acylamino-ketones.Historically, the dehydration agent is concentrated sulfuric acid. Recently, phosphorus oxychloride is successful with this reaction also....
  
   by dehydration of 2-acylaminoketones
• the Fischer oxazole synthesis
  Fischer oxazole synthesis
  The Fischer oxazole synthesis is a chemical synthesis of the aromatic heterocycle oxazole from cyanohydrins and aldehydes in the presence of anhydrous hydrochloric acid. This method was discovered by Hermann Emil Fischer in 1896.-References:...
  
   from cyanohydrins and aldehydes
• the Bredereck reaction with α-haloketone
  Haloketone
  A haloketone in organic chemistry is a functional group consisting of a ketone group or more general a carbonyl group with a α-halogen substituent. The general structure is RR'CCR where R is an alkyl or aryl residue and X any one of the halogens...
  
  s and formamide
  Formamide
  Formamide, also known as methanamide, is an amide derived from formic acid. It is a clear liquid which is miscible with water and has an ammonia-like odor. It is used primarily for manufacturing sulfa drugs and synthesizing vitamins and as a softener for paper and fiber...
  
  

Other methods are reported in literature.

• Oxazolines can also be obtained from cycloisomerization of certain propargyl
  Propargyl
  In organic chemistry, propargyl is an alkyl functional group of 2-propynyl with the structure HC≡C−CH2−, derived from the alkyne propyne.The term propargylic refers to a saturated position on a molecular framework next to an alkynyl group...
  
   amide
  Amide
  In chemistry, an amide is an organic compound that contains the functional group consisting of a carbonyl group linked to a nitrogen atom . The term refers both to a class of compounds and a functional group within those compounds. The term amide also refers to deprotonated form of ammonia or an...
  
  s.