Dear Daniyal Ahmed,

if I remember, benzoxazole can also be synthetized from o-aminophenol with triethyl orthoformate. Also if you have access to o-hydroxybenzophenone oximes, a Beckmann rearrangement in PPA could work. Photochemical procedures involving benzoisoxazole can be carried out to obtain benzoxazoles. 2-cyanophenol can also be used in photochemistry to access benzoxazole.

By reaction o- amino phenol and beta ketones https://www.google.com/url?sa=t&source=web&rct=j&url=http://pubs.acs.org/doi/full/10.1021/jo500604x%3Fsrc%3Drecsys&ved=2ahUKEwj6isTqjZTnAhXKzoUKHfh8C0cQFjACegQIBBAB&usg=AOvVaw3TMitLbMlOa5xvj2FA4Ztt

by refluxing of ortho-aminophenol with formyl chloride

By refluxing of ortho-aminophenol with ethyl formiate. Formyl chloride does not exist.

Thankyou All ! Corentin Lefebvre Rossen Buyukliev Banan Aldewachi Nagham Zaki .

ethyl formate is correct

@Rossen Buyukliev Thankyou Sir

But Can You Please Guide Me If There’s Any Medium To Maintain During Refluxing??

Synthesis of benzoxazole can be achieved by heating o-aminophenol with carboxylic acid in presence of polyphosphoric acid. In another method o-amino phenol is heated with HC(OCH3)3 in presence of HCl.

Dear Sir Madhukar Baburao Deshmukh ,

Can You Please Guide Me , How Much Temperature Is Required Or The Conditions Involved In The First Method Where PPA

Is Used As A Solvent.

Suggestion Would Be Helpful.

Thankyou

The reaction of ortho-substituted anilines with functionalized orthoesters yields benzoxazole, benzothiazole, and benzimidazole derivatives in an efficient and connective methodology.

here is link

https://pubs.acs.org/doi/abs/10.1021/ol301472a

Thankyou Ramnath Mallah For Suggestion!

To synthesis of benzoxazole is achieved by reacting o-aminophenol with aryl or alkyl aldehyde to form Schiff,s base followed by cyclization of it in presence of H2SO4 to get benzoxazole.

In another method o-amino phenol is heated with ethyl chloroformate with formaldehyde to form 1,3-benzoxazole.

I suggest the method of Prof Madhukar Baburao Deshmukh.

My research group develop various method to synthesize benzoxazole compounds with good yield using various abundant catalyst that you can find. This is my paper in the preparation of benzoxazole and benzothiazole using simple organic dye as catalyst, you can have a look at it: Article Straightforward synthesis of benzoxazoles and benzothiazoles...

furthermore, some other mild condition develop from our research group for benzoxazole, benzothiazole and benzimidazole: https://www.thieme.de/en/thieme-chemistry/synform-news-novel-synthesis-of-benzoxazoles-and-benzimidazoles-153650.htm

Nguyen Hoang Long Madhukar Baburao Deshmukh Ramin Javahershenas Thankyou For Your Informative Response.

My research work is the synthesis and arylation of heteroarenes by using various methods. Recently I was prepared benzoxazoles with formaldehyde in the presence of H2SO4 from o-aminophenol in good to excellent yields.