3404-93-1Relevant academic research and scientific papers
Chemistry of naphthazarin derivatives 8. Determination of structures of substituted 2-hydroxy-6(7)-methoxynaphthazarins and 7(8)-hydroxypyranonaphthazarins by IR spectroscopy
Glazunov,Tchizhova,Shestak,Sopel'nyak,Anufriev
, p. 95 - 100 (2001)
A set of substituted 2-hydroxy-6(7)-methoxynaphthazarins and 7(8)-hydroxypyranonaphthazarins were synthesized. The IR spectra of 2-hydroxy-6-methoxynaphthazarins and 7-hydroxypyranonaphthazarins, on the one hand, and of 2-hydroxy-7-methoxynaphthazarins an
Trimethyl orthoacetate as a convenient reagent for selective methylation of β-OH groups of (poly)hydroxynaphthazarins
Balaneva,Shestak,Novikov
, p. 55 - 63 (2019/04/25)
Trimethyl orthoacetate was found to be a convenient reagent for methylation of the β-OH groups of (poly)hydroxynaphthazarins. The substrates bearing one β-OH group react with MeC(OMe)3 to give the corresponding methoxy derivatives in 79–89% yields. Depending on the reaction conditions, methylation of substrates with two β-OH groups on the different and the same rings affords either the corresponding mono-O-methylated (43–70%) or di-Omethylated (71–78%) derivatives. Trimethyl orthoacetate offers a good alternative to CH2N2 in the preparative synthesis of O-methylated (poly)hydroxynaphthazarin derivatives.
First direct observation of tautomerism of monohydroxynaphthazarins by IR-spectroscopy
Glazunov, Valery P.,Tchizhova, Alla Ya.,Pokhilo, Nataly D.,Anufriev, Victor Ph.,Elyakov, George B.
, p. 1751 - 1757 (2007/10/03)
Some substituted monohydroxylated naphthazarins (5,8-dihydroxy-l,4-naphthoquinones) were synthesized and studied by IR-spectroscopy in aprotic organic solvents at ambient temperature. Two narrow stretching mode bands in the high frequency range 3540-3410
