Question

Where can I find the detailed synthesis of Maltol complex Al(III) and Cu(II). I need to write an experimental protocols for each synthesis.

Answer 1

Synthesis of maltol complex Al 3

By alkaline hydrolysis of streptomycin salts; also from piperdine to pyromeconic acid and subsequent methylation at the 2 position.

It is produced when cellulose or starch is heated and is a constituent of wood tar oils. It forms crystals (mp 162 -164 deg C) with a caramel-like odor, reminiscent of freshly baked cakes. Maltol can be produced synthetically starting from kojic acid or isolated from beechwood tar or extracts of needles from the genus Abies. Commercially available extracts from Abies balsamea needles, which are also used as flavor and fragrance materials, usually contain 3-8% maltol.

Cu 2

To prepare the copper(II) complexes (1 and 2) a common procedure (Scheme 1) was followed as described below, using copper(II) chloride for complex (1), copper(II) bromide (2), and the organic ligand (HL) in equimolar (1 : 1) ratio. A methanolic solution of HL (1.0 mmol) was mixed with 1.0 mmol of copper(II) chloride (1) and copper(II) bromide (2) with stirring condition and the mixture was refluxed for 4 h. The solid product was collected by filtration and washing with cold methanol and water then dried in vacuo. The pure crystallized product was obtained from methanol.

[Cu(L)(Cl)(H2O)] (1): yield 80–85%; C17H15N2O2 CuCl

Complex-1: C17H15N2O2CuCl: Anal. Found; C, 53.96; H, 3.96; N, 7.40; Cu, 16.81; Calc: C, 53.84; H, 3.92; N, 7.34; Cu, 16.72. IR (cm−1): vCH=N, 1618; vC=N, 1470, vO–H, 3438. m.p. 232 ± 1°C. ESI MS (): M+ 378, [M+2]+ 380. Magnetic moment (μ, B.M.): 1.74. Conductivity (Λo, S cm−1) in DMF: 6.32.

[Cu(L)(Br)(H2O)] (2): yield 75–80%; C17H15N2O2 CuBr

Complex-2: C17H15N2O2CuBr: Anal. Found; C, 48.29; H, 3.55; N, 6.62; Cu, 15.03; Calc: C, 48.18; H, 3.48; N, 6.54; Cu, 14.82. IR (cm−1): vCH=N, 1620; vC=N, 1468, vO–H, 3440. m.p. 243 ± 1°C. ESI MS () M+ 422, [M+2]+ 424. Magnetic moment (μ, B.M.): 1.72. Conductivity (Λo, S cm−1) in DMF: 6.30.