Synthesis 2021; 53(14): 2494-2502
DOI: 10.1055/a-1399-3823
paper

N-Acylbenzotriazoles as Proficient Substrates for an Easy Access to Ureas, Acylureas, Carbamates, and Thiocarbamates via Curtius Rearrangement Using Diphenylphosphoryl Azide (DPPA) as Azide Donor

Mangal S. Yadav
,
Sumt K. Singh
,
Anand K. Agrahari
,
Anoop S. Singh
,
The authors sincerely thank the Science and Engineering Research Board (SERB), New Delhi (Grant No. EMR/2016/001123) and the Council of Scientific and Industrial Research (CSIR), New Delhi [Scheme No. 02(0345)/19/EMR-II] for funding. M.S.Y. and A.K.A. acknowledge CSIR for fellowships (SRF), while S.K.S. thanks the University Grants Commission (UGC) for a JRF.


This manuscript is dedicated to the late Prof. Alan R. Katritzky for his notable contributions to benzotriazole chemistry.

Abstract

A diverse range of ureas, N-acylureas, carbamates, and thiocarbamates has been synthesized in good to excellent yields by reacting N-acylbenzotriazoles individually with amines or amides or phenols or thiols in the presence of diphenylphosphoryl azide (DPPA) as a suitable azide donor in anhydrous toluene at 110 °C for 3–4 hours. In this route, DPPA was found to be a good alternative to trimethylsilyl azide and sodium azide for the azide donor in Curtius degradation. The high reaction yields, one-pot and metal-free conditions, straightforward nature, easy handling, use of readily available reagents, and in many cases avoidance of column chromatography are the notable features of the devised protocol.

Supporting Information



Publication History

Received: 13 January 2021

Accepted after revision: 24 February 2021

Accepted Manuscript online:
24 February 2021

Article published online:
16 March 2021

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