Funnel, Buchner dropping

Pressure-equalizing dropping funnel Buchner flask (1 L)... 

Grind 25 g. of anthraniUc acid with 46 ml. of concentrated hydrochloric acid and 75 ml. of water in a glass mortar, and transfer the suspension to a 500 ml. round-bottomed flask which is provided with a mechanical stirrer. Cool the contents of the flask in an ice bath to 0-5°, and add a solution of 13-2 g. of sodium nitrite in 175 ml. of water from a dropping fimnel during about 20 minutes. Keep the diazonium solution below 6° and, if it is not clear, filter it by suction through a chilled Buchner funnel immediately before use. 

A. Heptoic anhydride enanthic anhydride). In a 250-ml. round-bottomed three-necked flask, equipped with a stirrer, dropping funnel, and thermometer, are placed 15.8 g. (16.1 ml., 0.2 mole) of dry pyridine (Note 1) and 25 ml. of dry benzene (Note 2). I hen 14.8 g. (15.5 ml., 0.1 mole) of heptoyl chloride (Note 3) is added rapidly to the stirred solution. The temperature rises only slightly, and a pyridinium complex separates. While stirring is continued, 13.0 g. (14.1 ml., 0.1 mole) of heptoic acid (Note 3) is added from the dropping funnel over a period of 5 minutes. The temperature rises rapidly to 50-65° (Note 4), and pyridine hydrochloride is formed. After stirring for 10 minutes, the solid is collected on a chilled Buchner funnel and washed twice with 25-ml. portions of dry benzene (Note 5). 

Add 2.0 g of salicylic acid, 5.0 mL of acetic anhydride, and 5 drops of 85% H3P04 to a 50-mL Erlenmeyer flask. Heat in a water bath at 75°C for 15 minutes. Add cautiously 20 mL of water and transfer to an ice bath at 0°C. Scratch the inside of the flask with a stirring rod to initiate crystallization. Separate aspirin from the solid-liquid mixture by filtering through a Buchner funnel 10 cm in diameter. 

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