Rapid Solvent-free Synthesis of Aromatic Hydrazidesunder Microwave Irradiation

Abstract

A variety of aromatic hydrazides has been synthesised by solvent-free hydrazinolysis of corresponding esters with hydrazine hydrate under microwave irradiation.

Lehrstück über Geschichte

“…These ester yielded corresponding hydrazide on refluxing with hydrazine hydrate for 3–5 h [13]. The analytical and spectral data of hydrazides were in complete agreement with those given in literature [13–17]. Hydrazides on reaction with carbon disulphide and potassium hydroxide afforded thiocarbazate salts, which are cyclized in the presence of concentrated sulfuric acid to afford 5‐substituted‐1,3,4‐thiadiazole‐2‐thiols.…”

“…The product obtained was recrystallized from methyl alcohol. The hydrazides were characterized on the basis of physical and spectral data [13–17].…”

Rapid Solvent-Free Microwave Assisted Synthesis of Some N’-Benzylidene Salicylic Acid Hydrazides

“…The product obtained was 2-hydroxybenzohydrazide (3) in 78% yield as previously reported [7]. The corresponding N'-benzylidene-2-hydroxybenzohydrazides (5a-h) obtained by condensation reaction of 2-hydroxybenzohydrazide (3) and substituted benzaldehydes (4a-h).…”

“…The synthesis of 2-hydroxybenzohydra zide has been successfully done in high yield [7]. Various long chain aliphatic acid hydrazides react with by microwave irradiation technique [9].…”

Farmakológiailag aktív 17-exo-heterociklusos szteroidok szintézise

“…Az irodalmi áttekintésből kitűnik, hogy a szteránváz 17-es helyzetében izoxazolokkal, A karbonsavhidrazidok egy részét (35ad) MW-besugárzás mellett metil-benzoát (34a), valamint heteroaromás észterek (34bd) és hidrazin-hidrát nukleofil acil szubsztitúciós reakciójával nyertük [153,154], majd a termékeket a feldolgozást követően tisztítás nélkül használtuk fel (32. ábra). A szteroid-karbaldehidek (32 és 33) és acil-hidrazinok (35ae) kondenzációs reakcióit hagyományos melegítés és MW-technika alkalmazásával is végrehajtottuk.…”