W-Chlorobenzaldehyde

Figure 2 FTIR spectra of /w-chlorobenzaldehyde adsorbed on MgO (a) After lmin exposure of w-chlorobcnzaldchydc at 70°C (b) after 30 min exposure of w-chlorobenzaldchydc at 70°C (c) after 5 min exposure at 110°C (d) after 5 min exposure at 130°C and (e) after 5 min exposure at 160°C.

The following aldehydes may be condensed in similar manner to the above procedure to give the corresponding substituted 9-benzal-fluorene of the indicated melting point. o-Tolualdehyde, m.p. 109.5° p-chlorobenzaldehyde, m.p. 149.5° w-chlorobenzaldehyde, m.p. 90.5° and m-bromobenzaldehyde, m.p. 92-93°. 

This procedure is adapted from the preparation described by Marvel and Schertz. w-Chlorophenylmethylcarbinol also has been prepared from w-chlorobenzaldehyde and methylmagnesium iodide. ... 

The diazonium solution is added to the hot cuprous chloride solution while the latter is shaken by hand but is not cooled. After the solutions are thoroughly mixed, 840 cc. of concentrated hydrochloric acid is added, and the mixture is allowed to stand overnight. The reaction mixture is steam-distilled to separate the w-chlorobenzaldehyde, which is collected practically completely in the first 1500 cc. of distillate. The w-chlorobenzalde-hyde is removed from the aqueous distillate by extraction with two 150-cc. portions of ether, and the ethereal solution is dried with 10-15 g. of anhydrous calcium chloride. After being decanted from the drying agent, the ether is distilled, and the residual liquid is distilled under diminished pressure. The m-chlorobenzaldehyde boils at 84-86°/8 mm., io7-i09°/26 mm. (Note 5). The yield is 70-74 g. (75-79 per cent of the theoretical amormt) (Note 6). 

The diazonium chloride solution is added with shaking to a copper(i) chloride solution at 75° the mixture is then treated with concentrated HC1 (840 ml), set aside overnight and worked up by distillation in steam. w-Chlorobenzaldehyde, which passes over with the first 1.51 of distillate, is extracted in ether (2 X 150 ml), being obtained in 75-79% yield with b.p. 84-86°/8 mm, 107-109°/26 mm. 

Resonance stabilization of the carbonyl group is generally not accompanied by a resonance stabilization of the product hydrate (Fig. 16.30). For example, the aromatic aldehyde, w-chlorobenzaldehyde (Table 16.3), is more strongly stabilized by resonance than acetaldehyde. There is no corresponding difference in the hydrates, and therefore the aromatic aldehyde is less hydrated at equilibrium than acetaldehyde. 

CS2 or CC14), mp 95-96°, bp 310-15°) sol in acet benz si sol in w can be prepd by condensing 2-chlorobenzaldehyde with malononitrile. The physiological effect of this compd is to cause sneezing skin irritation the smarting effect is intensified by washing. Most of the discomfort can be avoided if a... 

Holland, P. and White, R.G., The cutaneous reactions produced by o-chlorobenzaldehyde malononitrile and w-chloroacetophenone when applied directly to the skin of human subjects, Br. J. Dermatol, 86, 150-154, 1972. 

High-boiling alcohols are sometimes better dehydrogenated in the liquid phase in presence of a hydrogen-acceptor such as copper and nitrobenzene or w-dinitrobenzene. The preparation of o-chlorobenzaldehyde in 86% yield from 2-chlorobenzyl alcohol at 205-210° may be cited as example.432... 

A mixture of 1 mole phenyl isocyanide and 2 moles p-chlorobenzaldehyde in ether or tetrahydrofuran added dropwise to 1 mole tri-n-butylborane -> 2,2-di-n-butyl-4,5-di-p-chlorophenyl-3-phenyloxazolidine. Y 72%. G. Hesse, H. Witte, and W. Gulden, Ang. Gh. 77, 591 (1965). 

A soln. of triphenylarsine and 9-bromofluorene in nitromethane warmed 1 hr. on a steam bath triphenylfluorenylarsonium bromide (Y 83%) dissolved in abs. ethanol, stirred, and treated portionwise at room temp, with 2.5 N NaOH-soln. triphenylarsoniumfluorenylide (Y 78%) dissolved in chloroform, treated with p-chlorobenzaldehyde, and refluxed 3 hrs. -> p-chlorobenzalfluo-rene (Y 98%) and triphenylarsine oxide (Y 98%).—Triphenylarsoniumfluorenylide is the first example of an isolable As-ylide. F. reactions with aldehydes s. A. W. Johnson, J. Org. Ghem. 25, 183 (1960). 

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