Zur Kenntnis der Thiazol‐2‐carbonsäure

Thiazolecarboxylic Acids, Thiazolecarboxaldehydes, and Thiazolyl Ketones

“…The esters are generally prepared by heterocyclization (d. Chapter 11), the most useful and versatile of which is the Hantzsch's synthesis, that is the condensation of an halogenated a-or /3 keto ester with a thioamide (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). For example ethyl 4-thiazole carboxylate (3) was prepared by Jones et al from ethyl a-bromoacetoacetate (1) and thioformamide (2) (1).…”

Cu(I)-Catalyzed Three-Component Cyclization for the Construction of Functionalized Thiazoles

“…Main synthetic routes including transition metal-catalyzed arylation reactions of a parent thiazole allow the divergent synthesis of arylthiazoles. − However, the parent thiazole must be prefunctionalized with a halogen or a metal group prior to cross-coupling. As a convergent and classical method for the synthesis of thiazoles, Hantzsch thiazole synthesis provided the access to connect α-haloketones and thioamides in a simple manner (Scheme a) . Later on, Chan’s group reported a p -TsOH 3 ·H 2 O-catalyzed cyclization of trisubstituted propargylic alcohols with thioamides to prepare 2,4-di- and trisubstituted thiazole products (Scheme b) .…”

Late-Stage C–H Coupling Enables Rapid Identification of HDAC Inhibitors: Synthesis and Evaluation of NCH-31 Analogues

“…When following the classical condensation reaction to make NCH-31 derivatives, one needs to start from acetophenone derivatives to modify aryl groups; bromination of acetophenones, thiazole formation with thiourea, condensation with carboxylic acids, and introduction of the thiol unit. 13 An ideal, step-economical, diversity-oriented approach would be to introduce aryl groups onto a thiazole core of NCH-31 at the late stage of the synthesis. In doing so, we envisioned that the application of our recently developed unique Pd catalyst that promotes otherwisedifficult C4-selective C−H arylation of thiazoles with arylboronic acids should perfectly match this requirement ( Figure 2).…”

“…In planning synthesis of NCH-31 derivatives, we realized that step-economical, late-stage C–H functionalization approach should be taken rather than following our previous synthesis of NCH-31 using Hantzsch thiazole synthesis (Figure ). When following the classical condensation reaction to make NCH-31 derivatives, one needs to start from acetophenone derivatives to modify aryl groups; bromination of acetophenones, thiazole formation with thiourea, condensation with carboxylic acids, and introduction of the thiol unit . An ideal, step-economical, diversity-oriented approach would be to introduce aryl groups onto a thiazole core of NCH-31 at the late stage of the synthesis.…”