thiourea and aniline

Organic reactions performed in the absence of solvent in domestic ovens without appropriate temperature control are generally considered as not reproducible, particularly when different instruments are used. For this reason, reproducibility has historically been one of the major issues associated with Microwave-Assisted Organic Synthesis (MAOS) especially when domestic ovens are involved. The lack of reproducibility limits the general applicability and the scale up of these reactions. In this work several solvent-free reactions previously carried out in domestic ovens have been translated into a single-mode microwave reactor and then scaled up in a multimode oven. The results show that most of these reactions, although not considered as reproducible, can be easily updated and applied in microwave reactors using temperature-controlled conditions. Furthermore, computational calculations can assist to explain and/or predict whether a reaction will be reproducible or not.

Topics: Alkylation; Aniline Compounds; Bromides; Chemistry, Organic; Combinatorial Chemistry Techniques; Microwaves; Oxidation-Reduction; Pyridines; Reproducibility of Results; Temperature; Thiourea; Triazoles; Urea

A traceless solid supported protocol for the synthesis of 2-aminobenzothiazoles is described, employing resin-bound acyl-isothiocyanate and a series of anilines. Cyclization of the resulting N-acyl, N'-phenyl-thioureas generates the 2-aminobenzothiazole scaffold, which can be further elaborated prior to hydrazine-mediated cleavage of the final products from the carboxy-polystyrene resin. A small, focused library of 2-aminobenzothiazoles was prepared.

Topics: Aniline Compounds; Benzothiazoles; Crystallography, X-Ray; Cyclization; Hydrazines; Isothiocyanates; Molecular Conformation; Thiourea