A.
2-Nitro-6-methoxybenzonitrile. Five hundred grams
(2.97 moles) of technical m-dinitrobenzene (m.p.
88–89°) is dissolved in
7.5 l. of absolute methanol in a
12-l. round-bottomed flask fitted with an
efficient mechanical stirrer. The temperature is raised to 40° by means of a
water bath and maintained there while a solution of
230 g. of potassium cyanide in 400 ml. of water is added with stirring. The dark purple mixture is stirred for 2 hours and then is allowed to stand at room temperature for 2–3 days. The black precipitate is collected with suction on a
Büchner funnel, pressed as dry as possible, and then spread out in the air to dry. It weighs about 185–188 g.
The filtrate is diluted with 60 l. of cold water (Note
1) and allowed to stand overnight. The brown sludge is filtered with suction (Note
2) and pressed as dry as possible on the funnel. After drying, it weighs about 164 g. The combined precipitates are refluxed for 30 minutes each with successive
650-, 500-, and 500-ml. portions of chloroform. The
chloroform extracts are filtered while hot, and the bright red filtrates are combined and concentrated to a volume of 500 ml. by distillation.
One liter of petroleum ether (b.p.
60–90°) is added, whereupon the crude
2-nitro-6-methoxybenzonitrile separates as a red powder. It is removed by filtration and air-dried. It weighs
120–125 g. (
22–23%) and melts at
148–157° (Note
3). It is used without purification (Note
4).