- Small molecule library synthesis using segmented flow
-
Flow chemistry has gained considerable recognition as a simple, efficient, and safe technology for the synthesis of many types of organic and inorganic molecules ranging in scope from large complex natural products to silicon nanoparticles. In this paper
- Thompson, Christina M.,Poole, Jennifer L.,Cross, Jeffrey L.,Akritopoulou-Zanze, Irini,Djuric, Stevan W.
-
experimental part
p. 9161 - 9177
(2012/01/03)
-
- The Hantzsch Thiazole Synthesis under Acidic Conditions: Change of Regioselectivity
-
The condensation of α-halogeno ketones with N-monosubstituted thioureas in neutral solvent leads exclusively to 2-(N-substituted amino)thiazoles.In the present work it was shown that under acidic conditions mixtures of 2-(N-substituted amino)thiazoles and 3-substituted 2-imino-2,3-dihydrothiazoles are formed. (The isomers were distinguished by characteristic differences between their 5-H 1H n.m.r. signals and the i.r.CO bands of their trifluoroacetate derivatives.) The proportions of the 2-imino-2,3-dihydrothiazoles in the mixtures are influenced by experimental features and by the structures of the starting materials.Reactions in 10 M-HCl-EtOH (1:2) at 80 deg C for 20 min were found to be the most efficient for generating 2-imino-2,3-dihydrothiazoles; in the most favourable case 2-imino-3,4-dimethyl-2,3-dihydrothiazole was obtained in 73 percent yield.A possible explanation of the results is discussed.
- Bramley, (Miss) Susan E.,Dupplin, Viscount,Goberdhan, Dhanesh G. C.,Meakins, G. Denis
-
p. 639 - 644
(2007/10/02)
-