Aroyl cyanides synthesis

A simple and elegant one-pot synthesis of 3-amino-4-arylfurazans from the corresponding aroyl cyanides was developed by Lakhan and Singh (Scheme 102) [87IJC(B)690]. 

Scheme 5.19 Ketone synthesis via aroyl cyanides developed by Knochel s group.

A new primary synthesis of 2-amino-3-arylpyrazines is accomplished by reaction of aroyl cyanides with 1,2-diaminoethane (Scheme 33). An important synthesis is that of 2-amino-3-cyano-5-sub-stituted pyrazines, which are conveniently synthesized by condensation of aminomalononitrile with a-oximino ketones and then deoxygenation of the resulting pyrazine jV-oxides (Scheme 37). 

Lakhan and Singh ° described the first direct synthesis of 4-amino-2,5-disub-stituted oxazoles 552 from readily available starting materials. They condensed equimolar amounts of an aroyl cyanide 551 and an aldehyde with anhydrous ammonium acetate to afford 552 in 40-65% yield (Scheme 1.151). The reaction works better for aroyl cyanides containing electron-withdrawing groups. The... 

This reaction was initially reported by Reissert in 1905 and extended by Grosheintz and Fischer in 1941 It is the synthesis of aldehyde involving the formation of 1 -acyl-2-cyano-1,2-dihydroquinoline derivatives from acyl chlorides, quinoline, and potassium cyanide and the subsequent hydrolysis of said dihydroquinoline derivatives under acidic conditions to produce quinaldic acid and aldehydes. The original procedure occurs smoothly for aroyl or cinnamoyl chloride in liquid SO2 but not in benzonitrile, ether, dioxane, acetone, or CHCb. However, the modification from Grosheintz and Fischer using hydrogen cyanide and 2 eq. quinoline in absolute benzene is also adaptable for aliphatic acid chlorides. This is one of the methods that converts acyl chlorides into aldehydes and is found to be superior to the normal Rosenmund Reduction. For example, o-nitrobenzoyl chloride has been converted into o-nitrobenzaldehyde in 60% yield by the current reaction, whereas the Rosenmund Reduction is not suitable for such conversion. Therefore, this reaction is referred to as the Grosheintz-Fischer-Reissert aldehyde synthesis or Reissert aldehyde synthesis. ... 

This was later exploited in a synthesis of 3-nitro-2i7-chromenes [212] with a variety of electron withdrawing substituents in moderate to good yield (Scheme 99). In 1983 Ando et al. [117] had reported the synthesis of aroyl nitriles from the corresponding chlorides by direct displacement with potassium cyanide [213]. 

E. C. Taylor, A. McKillop, and coworkers. Thallium in organic synthesis 49. Oxidative rearrangement of chalcone dimethylketals to methyl-2,3-diaryl-3-methoxypropanoates with thallium(m) trinitrate in trimethylorthoformate. J. Org. Chem., 1977, 42, 4167 50. A convenient synthesis of thallium(i) cyanide, a useful reagent in organic synthesis (for conversion of aroyl chlorides to aromatic a-ketonitriles). J. Org. Chem., 1978, 43, 2280 51. Oxidation of enolizable ketones to a-nitratoketones by thallium(in) nitrate in acetonitrile. 

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