Organic Syntheses, CV 3, 504
Submitted by D. B. Glass and A. Weissberger.
Checked by Cliff S. Hamilton and Carol K. Ikeda.
1. Procedure
A mixture of
66.5 g (0.5 mole) of tetrahydroquinoline and
400 g. of trimethylene chlorobromide (Note
1) is placed in a
1-l. round-bottomed flask attached to a
reflux condenser, and heated in an
oil bath held at 150–160° for 20 hours (Note
2). The reaction mixture is cooled, a solution of
50 ml. of concentrated hydrochloric acid in 500 ml. of water is added, and the excess
trimethylene chlorobromide is removed by distillation with steam (Note
3). The acid residue from the steam distillation is made alkaline with a
40% solution of sodium hydroxide (about 75 ml.), and the
julolidine is extracted with two
150-ml. portions of ether. The ethereal solution is washed with 150 ml. of water and dried over
sodium hydroxide pellets. The
ether is evaporated and the residue distilled under reduced pressure. The portion that boils at
105–110°/1 mm. is collected (Note
4) and (Note
5). The yield is
67–70 g. (
77–81%).
2. Notes
2. The heating should be carried out in a
hood, or a
gas trap should be used to remove the hydrogen halides that are evolved.
4. The
julolidine solidifies in the
receiver, m.p.
39–40°.
5. After standing in contact with air for several weeks, the
julolidine may become colored by the formation of a red compound. This red compound may be removed by distillation or by dissolving the amine in
2 or 3 volumes of hexane, treating the
hexane solution with
Norit or Darco, and filtering. The
julolidine is crystallized from the
hexane solution by cooling in an
acetone-Dry Ice bath. The resulting product melts at
39–40° and amounts to
85–90% of the original.
3. Discussion
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