An efficient and selective way to new highly functionalized coronands or spiro derivatives using ultrasonic irradiation

Abstract

A new, selective, straightforward and general method for preparation of highly functionalized coronands or spiro derivatives bearing 1,2-dihydroxyacetophenone unit, under conventional conditions and ultrasonic irradiation, is reported. The reaction setup involves only one step, acylation of an α-chloro-3,4-dihydroxyacetophenone with phthaloyl dichloride derivatives. 1,3- and 1,4-Phthaloyl dichloride derivatives leads to coronands only, while 1,2-phthaloyl dichlorides lead either to coronands or to spiro derivatives. A feasible explanation for the different behavior between conventional and ultrasound methods could be the different reaction mechanism involved in the two procedures: tetrahedral nucleophilic substitution under conventional conditions and radical substitution under ultrasound. Ultrasound induces a remarkable acceleration of the reactions (from days to minutes) and, most significantly, the yields are twice as high. A feasible explanation for the efficiency of the reactions under ultrasonic irradiation is presented.

Reduction of Aldehydes Using Sodium Borohydride under Ultrasonic Irradiation

“…The procedure is very simple, energy efficient, and converted the aldehydes into corresponding alcohols in relatively high yield. Moreover, in many cases, sonication reactions under ultrasound irradiation could be considered environmentally benign processes, employing either no solvent or small amount of solvents and being less energy consumer [12], which offers minimal side reactions [13]. This reduction method is expected as an alternative to replace the conventional reduction method that still use a large amount of solvent with a relatively high energy consumption.…”

N,N′-(1,4-Phenylene)bis(4-chlorobutanamide)

“…For details and syntheses of chloroamides as precursors for new azamacrocycles see: Benaglia et al (2005); Harte & Gunnlaugsson (2006); Humphrey & Chamberlin (1997); Mangalagiu et al (2007); Zbancioc et al (2012). Table 1 Hydrogen-bond geometry (Å , ).…”

“…With the aim of synthesizing new chloroamides as precursors for new azamacrocycles (Zbancioc et al, 2012), we report the synthesis and crystal structure of the title compound C 14 H 18 Cl 2 N 2 O 2 , which represents a diamide with aliphatic arms, consisting of two moieties of butyryl chloride and a phenylenediamine unit. Amides are important building blocks in preparative macrocycle chemistry (Harte & Gunnlaugsson, 2006), due to their spectroscopic proprieties as well as to their arms ability to coordinate to metal centers.…”

Synthesis of Amido Sulfonamido Heteroaromatics Under Ultrasonication and Their Antimicrobial Activity

“…Generally, ultrasonication is effective at room temperature when compared with conventional thermal methods. Moreover, ultrasound irradiation has typical advantages, viz ., substantial decrease of reaction time, increased selectivity, improved yields, high purity of the compounds and green reaction conditions . As per our ongoing research program aimed at the development of newer synthetic methodologies for the synthesis of molecules with a variety of pharmacophoric units, we herein report the synthesis of heteroaromatics linked by amido and sulfonamido moieties under ultrasonic irradiation.…”