Microwave-Enhanced Synthesis of Phosphonoacetamides

Abstract

An efficient microwave protocol is described for the Michaelis-Arbuzov synthesis of secondary and tertiary N-aryl (and alkyl) (diethylphosphono)acetamides 1, by reaction of chloro-and bromoacetamides with triethyl phosphite in the presence of catalytic amounts of sodium iodide. Remarkable acceleration of the reaction (minutes vs. several hours) over conventional heating was achieved, together with improved product yields and purity, when bromoacetamides were employed as the substrates. Chloroacetamides were comparatively less reactive, leading to satisfactory yields only when a high excess of the reagent was employed.

A demonstration of athermal effects of continuous microwave irradiation on the growth and antibiotic sensitivity ofPseudomonas aeruginosaPAO1

“…However, there a few claims that microwaves affect the activation energy for a chemical reaction in way not easily attributable to purely thermal effects as predicted by the Arrhenius equation. [12][13][14][15] Interestingly, there are claims that microwaves do affect the rate of enzyme catalysed conducted athermally in vitro [16][17][18][19] which could have consequences for viability. significantly when the cell culture enter stationary phase.…”

“…Indeed, even for chemical reactions it is very difficult to critically compare different experiments as they have been carried out under a wide range of conditions and are often reported in insufficient detail to allow reliable replication. However, there a few claims that microwaves affect the activation energy for a chemical reaction in way not easily attributable to purely thermal effects as predicted by the Arrhenius equation . Interestingly, there are claims that microwaves do affect the rate of enzyme catalysed conducted athermally in vitro which could have consequences for viability.…”

Microwave‐Assisted Synthesis of Isopropyl β‐(3,4‐Dihydroxyphenyl)‐α‐hydroxypropanoate

“…Owing to its advantages over the conventional heating method, microwave heating has been applied to a wide range of organic synthesis processes [6][7][8][9], following the pioneering work by Gedye et al [10] and Giguere et al [11] in the 1980s. The main advantages include the acceleration of reaction rate [12][13][14], improved product selectivity [15][16][17][18], and high yield [18][19][20]. The application of microwave heating has also been explored in the field of organic synthesis for drug discovery [21,22].…”