2-Amino-5-methylthiazole synthesis

9synthesis methods

Product Name:2-Amino-5-methylthiazole
CAS Number:7305-71-7
Molecular formula:C4H6N2S
Molecular Weight:114.17

2-Methyl-4-hydroxy-2H-1,2-benzisothiazine-3-carboxylic acid ethyl ester-1,1-diox

35511-15-0
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$75.00/5 g

71125-38-7 Synthesis

71125-38-7
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7305-71-7
456 suppliers
$6.00/10g

Yield:7305-71-7 90%

Reaction Conditions:

with montmorillonite MK₁₀ impregnated with ZnCl₂ in o-xylene for 24 h;Reflux;Green chemistry;Reagent/catalyst;

Steps:

Synthesis of 4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carbox-amide-1,1-di-oxyde (3) with impregnated MK10 (Zn-MK10) as catalyst
2-Amino-5-methylthiazole (85 mg, 0.7 mmol) and Zn-MK10 (30 mg, 0.037 mmol) were added to a solution of methyl 2-methyl-4-hydroxy-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide 4a (200 mg, 0.7 mmol) in o-xylene (3 mL) and the mixture was stirred at reflux during 24 h. After cooling to room temperature, the mixture was filtered to recover the supported catalyst, the xylene was evaporated and CH2Cl2 (10 mL) was added to the crude. The mixture was then purified on flash chromatography (EtOAc:n-heptane, 00:100 to 50:50) to provide the 4-hydroxy-2-methyl-N-(5-methyl-2-thiazolyl)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxyde (3) in 90% yield. White solid; mp 245-246 °C (CH2Cl2); Rf 0.62 (EtOAc:n-Heptane, 60:40), IR ν cm- 1: 3288, 1549, 1344, 1264, 1183 (Fig. 2). 1H NMR (400 MHz, CDCl3) δ (ppm): 2.46 (s, 3H, CH3), 2.89 (s, 3H, CH3), 7.23 (s, 1H, thiazolylH), 7.75 (dquint, J = 7.2, 1.6 Hz, 2H, ArH), 7.91 (dd, J = 7.4, 2.0 Hz, 1H, ArH), 8.06 (dd, J = 8.2, 1.6 Hz, 1H, ArH) (Fig. 3). 13C NMR (100 MHz, DMSO-d6) δ (ppm): 11.8 (CH3), 38.0 (CH3), 114.3 (C), 123.3 (CH; C), 126.1 (CH), 129.3 (CH), 132.1 (CH), 132.9 (CH; C), 134.4 (2C), 155.7 (C), 168.4 (C) (Fig. 4).

References:

Dufrénoy, Pierrick;Ghinet, Alina;Hechelski, Marie;Da?ch, Adam;Waterlot, Christophe [Journal of the Iranian Chemical Society,2019,vol. 16,# 3,p. 501 - 509]

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