Synlett 2003(4): 0564-0566
DOI: 10.1055/s-2003-37530
LETTER
© Georg Thieme Verlag Stuttgart · New York

An Efficient and Fast Procedure for the Preparation of 2-Nitrophenylamines under Microwave Conditions

Zhi-Bin Xu, Ying Lu, Zong-Ru Guo*
Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, P. R. China
Fax: +86(10)83155752; e-Mail: zrguo@imm.ac.cn;
Further Information

Publication History

Received 21 January 2003
Publication Date:
26 February 2003 (online)

Abstract

2-Nitrophenylamines were prepared in good yields from 2-chloronitrobenzen (or 2-fluoronitrobenzene) and amines in the presence of anhydrous potassium fluoride under microwave irradiation and solvent free conditions.

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General Procedure: The preparation of N-(4′-methoxy-phenyl)-2-nitrophenylamine (3a) is representative for all synthesis.
p-Methoxy phenylamine (1.1 mmol), anhyd KF (1.1 mmol) and K2CO3 (1.1 mmol) were well powdered with a mortar and pestle. 2-Chloronitrobenzene (or 2-fluoronitrobenzene) (1.1 mmol) was then added to the mixture and mixed well in a glass vial. After irradiation under microwave (90 W), the mixture was treated with water and CH2Cl2. The organic layer was washed with 10% HCl and brine. The CH2Cl2 solution was dried over anhyd Na2SO4, evaporated and crystallized from petroleum ether (bp 60-90 °C) to give orange crystals [mp 83-86 °C (lit. ref. [4] : mp 89 °C)]. 1H NMR (CDCl3, 300MHz): δ = 3.85 (s, 3 H, OCH3), 6.72-8.19 (8 H, aromatic H), 9.41 (s, br, 1 H, NH). MS (EI) m/z = 244 [M+], 229 [M+ - 15].