Potential naphthoquinone antimalarials. 2-Acylhydrazino-1,4-naphthoquinones and related compounds

Efficient Synthesis of Aminonaphthoquinones and Azidobenzohydroquinones: Mechanistic Considerations of the Reaction of Hydrazoic Acid with Quinones. An Overview

“…Thus, when aminonaphthoquinones are desired, the use of a stronger acid than acetic acid, which is usually used, along with an inert atmosphere, a polar solvent, and a sufficient excess of sodium azide are essential in order to obtain the desired compounds under mild conditions and avoid the side reactions. These specific experimental conditions were effective for a variety of substrates, and in each case the yield was considerably improved (Table ). 8a,b,, The regioselectivity of the addition when applied on nonsymmetric substrates (compounds 16e,f ) is also improved in comparison to previous reports. 8b,,21a …”

“…2-Amino-1,4-naphthoquinone (19a). Following the general procedure, 280 mg (1.79 mmol) of naphthoquinone ( 16a ) afforded 297 mg (97%) of 19a as an orange powder: mp 202−204 °C (lit 21a. 204−205 °C); IR ν 3392, 1685, 1618 cm -1 ; 1 H NMR δ 8.07 (m, 2H), 7.68 (m, 2H), 6.01 (s, 1H), 5.14 (s, 2H); MS m/z 173 (M + , 89), 146 (52), 145 (25), 117 (15), 105 (74), 104 (40), 76 (100), 50 (42).…”

Gas‐phase dissociation of 1,4‐naphthoquinone derivative anions by electrospray ionization tandem mass spectrometry

“…[2] Numerous quinones are obtained from natural sources [3,4] and many can be synthesized. [5] Therefore, techniques for their characterization and structural elucidation have become mandatory from the perspective of clinical and preclinical trials.…”

Fragmentation studies of synthetic 2‐acylamino‐1,4‐naphthoquinones by electrospray ionization mass spectrometry

“…1,4‐Naphthoquinones have also been shown to display biological activities, and they can act as antituberculosis,5 antimalarial,6, 7 antimicrobial8 and antitumor agents,9 as well as, molluscicide,10 larvicide,10 and herbicide11 agents. A considerable number of naphthoquinones containing amine groups in their structure or on the nitrogen atom have been associated with different biological activities 12, 13.…”