Synthesis of 4- or 6-(3-Benzyl-2,3-Dihydrobenzo[d]Thiazol-2-yl)Phenol Derivatives by a Novel Three-Component Reaction

Abstract

A series of 4- or 6-(3-benzyl-2,3-dihydrobenzo[ d]thiazol-2-yl)phenol derivatives was synthesised by reaction of benzothiazole or 2,6-dimethylbenzothiazole with benzyl bromide in the presence of 2,6-dimethylphenol, 2,6-di- tert-butylphenol or 2- tert-butyl-4-methylphenol. The reactions proceeded in the presence of Et3N as a base and acetonitrile as solvent under reflux for 5 h in good yields.

A novel, simple, and facile synthesis of 3-(3-benzyl-2,3-dihydrobenzo[d]thiazol-2-yl)benzo[d]oxazole-2(3H)-thione derivatives

“…For example, the 1 H NMR spectrum of 6a exhibited a singlet at 4.13 ppm (2H, CH 2 ) and the aromatic and NCHN protons occurred multiplets 6.69-7.86 ppm (13ArH and NCHN). [17][18][19][20][21] The 13 C NMR spectrum of 6a showed 18 distinct resonances in agreement with the proposed structure. Product 6a displayed 13 C NMR resonances at 51.4, 94.3, and 183.1 ppm, respectively, for the CH 2 , the SCN, and C=S carbons.…”

“…In continuation of our studies on the application of both benzothiazole and 2-mercaptobenzoxazole in MCRs, [17][18][19] a new, easy, and efficient route for the synthesis of…”

Simple, novel, and efficient synthesis of ethyl 2-(2-(1H-indol-3-yl)benzo[d]thiazol-3(2H)-yl)-2-cyanoacetate or acetate via a three-component reaction

“…Aromatic protons with multiplets as follows were also present: δ = 6.70-8.30 ppm, m, 8ArH, 1 from S-CH and NC-CH. 1,2,[20][21][22][23][24] The C NMR spectrum of 6a showed 20 distinct resonances in agreement with the proposed structure. In addition, product 6a displayed 13C NMR resonances at δ = 14.5, 59.5, 69.7, 92.3, and 117.6 ppm, respectively, for the CO 2 CH 2 CH 3 , CO 2 CH 2 CH 3 , HC-CN, S-C-N, and CN carbons.…”

“…At the end, this compound 5 is converted into product 6 by a formal [1,3] hydrogen shift. 23,24,[28][29][30]…”

“…four signals as follows: δ = 1.12 ppm, t, 3H, 3J HH = 7.30 Hz, CO 2 CH 2 CH 3 , 4.10 ppm, q, 2H, 3J HH = 7.30 Hz, CO 2 CH 2 CH 3 , 7.46 ppm, s, 1H, HN-CH=C and 8.86 ppm, s, 1Hbr, HN-CH=C. Aromatic protons with multiplets as follows were also present: δ = 6.70-8.30 ppm, m, 8ArH, 1 from S-CH and NC-CH 1,2,[20][21][22][23][24]. The C NMR spectrum of 6a showed 20 distinct resonances in agreement with the proposed structure.…”