ChemicalBook CAS DataBase List 3-BROMO-4-CYANOBENZOIC ACID

3-BROMO-4-CYANOBENZOIC ACID synthesis

4synthesis methods

Product Name:3-BROMO-4-CYANOBENZOIC ACID
CAS Number:58123-69-6
Molecular formula:C8H4BrNO2
Molecular Weight:226.03

362527-61-5 Synthesis

362527-61-5
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58123-69-6
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Yield:58123-69-6 90%

Reaction Conditions:

Stage #1: ethyl 3-bromo-4-cyanobenzoatewith sodium hydroxide;ethanol;water in tetrahydrofuran; for 20 h;
Stage #2: with hydrogenchloride in tetrahydrofuran;ethanol;water;

Steps:

2

EXAMPLE 2; Preparation of 3-Bromo-4-cyanobenzoic acid; A solution of ethyl 4-amino-3-bromobenzoate (23.5 g, 96.3 mmol) in methylene chloride at -10° C. is treated dropwise with tert-butyl nitrite (14.0 mL, 118.4 mmol), followed by boron trifluoride diethyl etherate (18.4 mL, 146.5 mmol). The reaction mixture is allowed to come to room temperature, stirred for 4 h, diluted with ethyl ether and filtered. The filtercake is dried, dispersed in toluene, cooled to 0° C., treated with a solution of copper (I) cyanide (11.5 g, 129.2 mmol) and sodium cyanide (15.8 g, 323.1 mmol) in water, stirred at 0° C. for 30 min., warmed to 60° C., stirred for 1 h, cooled to room temperature and diluted with EtOAc and water. The organic phase is separated, dried over MgSO₄and concentrated in vacuo. The resultant residue is crystallized from ethyl ether/hexanes to give the ethyl ester of the title compound as an off-white solid, 18.6 g (76% yield). A solution of this ester (8.5 g, 33.6 mmol) in THF is treated with a solution of NaOH (30 mL, 2.5 N) and ethanol, stirred for 20 h, acidified with 2N HCl and extracted with ethyl ether. The ether extracts are combined, dried over MgSO₄and concentrated in vacuo. The resultant residue is crystallized from ethyl ether/hexanes to afford the title compound as a beige solid, 6.81 g (90% yield), identified by HNMR and mass spectral analyses. MS m/e 223 (M-H)⁺; ¹H NMR (400 MHz, DMSO-d₆) δ 8.05 (dd, J=9.76, 1.37 Hz 1 H), 8.09 (d, J=8.08 Hz, 1H), 8.29 (d, J=1.37 Hz, 1H).

References:

US2005/282825,2005,A1 Location in patent:Page/Page column 8