Synthesis 2020; 52(11): 1666-1679
DOI: 10.1055/s-0039-1690822
paper
© Georg Thieme Verlag Stuttgart · New York

Microwave-Assisted Synthesis of 2-Substituted 2-Thiazolines and 5,6-Dihydro-4H-1,3-thiazines

María C. Mollo
a   Universidad de Buenos Aires, CONICET, Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Junín 956, 1113 Buenos Aires, Argentina   Email: lorelli@ffyb.uba.ar
,
Juan A. Bisceglia
a   Universidad de Buenos Aires, CONICET, Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Junín 956, 1113 Buenos Aires, Argentina   Email: lorelli@ffyb.uba.ar
,
Natalia B. Kilimciler
a   Universidad de Buenos Aires, CONICET, Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Junín 956, 1113 Buenos Aires, Argentina   Email: lorelli@ffyb.uba.ar
,
Michele Mancinelli
b   Department of Industrial Chemistry ‘Toso Montanari’, University of Bologna, Viale del Risorgimento 4, 40136 Bologna, Italy
,
a   Universidad de Buenos Aires, CONICET, Departamento de Química Orgánica, Facultad de Farmacia y Bioquímica, Junín 956, 1113 Buenos Aires, Argentina   Email: lorelli@ffyb.uba.ar
› Author Affiliations
This work was supported by the University of Buenos Aires (Grant No. 20020170100189BA).
Further Information

Publication History

Received: 28 December 2019

Accepted after revision: 23 January 2020

Publication Date:
24 February 2020 (online)


Abstract

An efficient and general method for the synthesis of 2-substituted thiazolines and 5,6-dihydro-4H-1,3-thiazines is developed via microwave-assisted ring closure of ω-thioamidoalcohols promoted by ethyl polyphosphate (PPE). The cyclization reaction involves an SN2-type mechanism and features the advantages of very short reaction times, high yields and a predictable stereochemical outcome. The acyclic precursors are prepared in high overall yields by an improved diacylation–thionation–saponification sequence from commercially available ω-amino­alcohols. The whole process is metal-free and operationally simple.

Supporting Information