1232682-75-5Relevant academic research and scientific papers
A Highly Efficient Copper(I)-Catalyzed Cascade Reaction of o-Alkenylphenyl Isothiocyanates with Isocyanides Leading to 5H-Benzo[d]imidazo[5,1-b][1,3]thiazines
Hao, Wenyan,Huang, Jian,Jie, Shanshan,Cai, Mingzhong
, p. 6655 - 6660 (2015/10/29)
The highly efficient copper(I)-catalyzed cascade reaction of (E)-3-(2-isothiocyanatophenyl)acrylates and (E)-3-(2-isothiocyanatophenyl)acrylonitriles with isocyanides was explored. The method provides an expedient route for the synthesis of 5H-benzo[d]imidazo[5,1-b][1,3]thiazines in good to excellent yields by using CuCl (10 mol-%) as the catalyst and K3PO4 (2.0 equiv.) as the base in THF at 70 C. The reaction involves [3+2] cycloaddition and subsequent intramolecular C-S bond formation.
Synthesis of 2-(2-Dialkylamino-4 H -3,1-benzothiazin-4-yl)acetic acid derivatives and 2-(2-Thioxo-1,2,3,4-tetrahydroquinazolin-4-yl)acetic Acid derivatives
Fukamachi, Shuhei,Konishi, Hisatoshi,Kobayashi, Kazuhiro
experimental part, p. 1593 - 1598 (2010/06/21)
An efficient method for the preparation of 2-(4H-3,1-benzothiazin-4-yl) acetic acid derivatives and 2-(2-thioxo-1,2,3,4-tetrahydroquinazolin-4-yl)acetic acid derivatives has been developed. The reaction of 3-(2-isothiocyanatophenyl) propenoic acid derivatives with secondary amines in methanol at room temperature gave the corresponding thiourea intermediates, which on heating at reflux temperature cyclized by an attack of the sulfur atom on the propenoic moiety in a 1,4-addition manner, to give 2-(2-dialkylamino-4H-3,1-benzothiazin-4-yl)acetic acid derivatives in one pot. A similar sequence using primary amines in place of secondary amines afforded 2-[3-alkyl(or aryl)-2-thioxo-1,2,3,4- tetrahydroquinazolin-4-yl]acetic acid derivatives. Georg Thieme Verlag Stuttgart.
