Synthesis
To a 250 mL triple-necked flask were added sequentially 4. 9 g of methyl 5-bromo-2-methylnicotinate ( 0. 04 mol), anhydrous ethanol 40
mL, the corresponding amount of concentrated sulfuric acid, and phase transfer catalyst; a stirrer and a distillation apparatus were installed separately. Heat with stirring, gradually increase the temperature, evaporate the ethanol to the required liquid temperature, stop heating, natural cooling, about .
50 C. It is poured out, and the reactants are white solids at room temperature. Neutralize the product with saturated aqueous sodium carbonate to a pH of about 7 (some solid sodium carbonate may be added if the volume is too large) and extract with 20 of chloroform.
mL of chloroform, the combined organic layers were transferred to a reduced-pressure distillation flask, the chloroform was recovered at atmospheric pressure and then ethyl 5-bromo-2-methylnicotinate was distilled at reduced pressure, and the 92- to fraction was collected at 1. 06 kPa.
The fraction was collected at 1.06 kPa from 92 to , weighed and the yield was calculated.
