Multicomponent synthesis of diphenyl-1,3-thiazole-barbituric acid hybrids and their fluorescence property studies

Abstract

A series of novel diphenyl-1,3-thiazole linked barbituric acid hybrids (4) were prepared by two catalyst-free methods from readily available starting materials.

HFIP-Mediated Multicomponent Reactions: Synthesis of Pyrazole-Linked Thiazole Derivatives

“…5-(2,4-Diphenylthiazol-5-yl)-1,3-dimethylpyrimidine-2,4,6-(1H,3H,5H)-trione (10a). 34 The product was purified by crystallization in ethyl acetate. Yield 163 mg (83%); white solid; 1 (m, 3H), 7.47 (t, J = 10.0 Hz, 2H), 7.36 (t, J = 10.0 Hz, 1H), 3.18 (s, 6H).…”

“…5-(2,4-Diphenylthiazol-5-yl)-1,3-dimethylpyrimidine-2,4,6-(1H,3H,5H)-trione (10a). 34 The product was purified by crystallization in ethyl acetate. Yield 163 mg (83%); white solid; 1 H NMR (500 MHz, DMSO-d 6 ): δ 7.90 (d, J = 5.0 Hz, 2H), 7.80 (d, J = 5.0 Hz, 2H), 7.49 (t, J = 10.0 Hz, 2H), 7.43 (t, J = 10.0 Hz, 1H), 7.29 (t, J = 10.0 Hz, 2H), 7.19 (t, J = 10.0 Hz, 1H), 3.08 (s, 6H).…”

Mechanochemical Synthesis of Organic Dyes and Fluorophores

“…Mahata et al reported the synthesis of a series of diphenyl-1,3thiazoles linked with barbituric acid moiety by a simple, catalystfree mechanochemical method. 37 The hand-grinding of arylglyoxal (25), barbituric acid (26), and aryl thioamides (27) in a mortar, assisted by a small amount of water for LAG, provided the corresponding trisubstituted thiazole−barbituric acid (28) within 30 min in high yields (Scheme 7). The molecules displayed fluorescence properties with emission maxima ranging from 495−562 nm.…”

“…40 At first, rhodamine 6G (35) was ground with hydrazine hydrate in an agate mortar with a pestle for 10 min to obtain rhodamine 6G hydrazide (36) in 95% yield. It was further condensed with different aromatic aldehydes (37) by mortar and pestle grinding to afford the chemosensors (38) in excellent yields (Figure 2A). Each of them displayed selective recognition ability toward Cu 2+ ions in a "turn-on" manner by complex formation (Figure 2B).…”

Mechanochemical Syntheses of N-Containing Heterocycles with TosMIC

“…In addition, combination with other disciplines such as photochemistry, electrochemistry, or in situ spectros­copy paved the way for new creative synthetic strategies. Numerous scientific communities, including inorganic, main group, coordination, organometallic, catalytic, pharmaceutical, macromolecular, supramolecular, and organic chemistry, became involved. ,, In the latter, multicomponent reactions for preparing sulfur-containing and nitrogen-containing heterocycles have greatly benefitted from mechanochemical applications …”