Solvent-Free C-O Bond Formation under Microwave Irradiation

Solid samples placed in the bottom of the test tube were cooled in a cooling apparatus and were irradiated by Pyrex-filtered light transmitted by using a flexible light guide from a 250-W ultra-high-pressure mercury lamp. When the powdered lb was irradiated at 15 °C for 2 h, a quantitative amount of 3-(Af-methylanilino)-3-phenylphthalide 2b ([a]o21° (c 1.0, CHCI3)) was obtained. 

3 Solvent-Free C-O Bond Formation under Microwave Irradiation 

Keywords -octyl bromide, benzoic acid, Aliquat 336, microwave irradiation, -octyl benzoate 

To 10 mmoles of potassium carboxylate were added in a Pyrex flask 10 mmol of n-octyl bromide and 1 mmol of tetraalkylammonium salt (Aliquat 336 or BU4NB1 ). After shaking, the flask was introduced in the microwave oven (or in an oil bath for control experiments) for the indicated time. The temperature was measured by introducing a Quick digital thermometer in the sample just at the end of each inadiation. Organic products were recovered by a simple elution with 50 mL diethyl ether or methylene chloride and subsequent fdtration over 

Florisil to remove mineral salts and catalyst. Products were analyzed by GC, characterized by and NMR, IR and MS after purification. 

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