Ethyl (2Z)-chloro[(4-methoxyphenyl)hydrazono]ethanoate synthesis
- Product Name:Ethyl (2Z)-chloro[(4-methoxyphenyl)hydrazono]ethanoate
- CAS Number:473927-63-8
- Molecular formula:C11H13ClN2O3
- Molecular Weight:256.69
Preparation of ethyl (2Z)-chloro[(4-methoxyphenyl)hydrazono]ethanoate To p-anisidine (16 g, 0.129 mol) in conc. HCL (40 mL), 100 mL) H2O, cooled to -5° C. and sodium nitrite (9.4 g, 0.136 mol) in H2O (60 mL) was added. The reaction mixture was stirred at -5° C. for 20 min and a mixture of ethylchloroacetoacetate (22 g, 0.133 mol), ethanol (100 mL), sodiumacetate (32 g, 0.389 mmol), and H2O (400 mL) was added. The reaction was allowed to warm up to room temperature and stirred for 2h. The product precipitated as a black solid. It was filtered and dried (30 g). 1H-NMR (CDCl3) δ 8.28 (s, 1H), 7.18 (d, 2H), 6.90 (d, 2H), 4.41 (q, 2H), 3.80 (s, 3H), 1.42 (t, 3H) ppm.
Yield:473927-63-8 92.3%
Reaction Conditions:
Stage #1:4-methoxy-aniline with sulfuric acid;sodium bromide;sodium nitrite at 5 - 10; for 0.333333 h;
Stage #2:chloroacetic acid ethyl ester with sodium acetate in ethanol for 2 h;Temperature;Reagent/catalyst;
Steps:
1-3 Example 2
P-methoxyaniline (0.1 mol, 12.3 g),Add sulfuric acid (40 mL, 4 mol/L),Stir to dissolve, control temperature at 10 ° C,Add sodium bromide (1 mmol, 2 mg),Control the temperature below 5 °C,40% sodium nitrite solution (0.12 mol, 13 mL) was added in portions.After stirring for 20 minutes,Filtration, heating to 10 ° C, adding chloroacetoacetic acid (0.11 mol, 15.2 mL), sodium acetate (0.25 mol, 20.5 g) to the filtrate.150mL of ethanol / ether mixed solution (1:2), continue to stirThe reaction was stirred for 3 hours, poured into 400 mL of ice water, and the solid was precipitated, filtered, washed with water and dried to give a solid 23.7 g, yield 92.3%.The HPLC purity was 98.1%, and the mass spectrum and hydrogen spectrum were identical as in Example 1.
References:
Lianyungang Hengyun Pharmaceutical Co., Ltd.;Zhu Qiang;Li Yunfei;Xu Dandan;Shan Wenjun CN109956886, 2019, A Location in patent:Paragraph 0023; 0024; 0025; 0026-0030
