Cinnamoyl chloride, reduction

Acylation of the monosubstituted piperazine, 99 (obtainable by the protection-deprotection scheme outlined above), with cinnamoyl chloride gives the corresponding amide (100). Reduction of the carbonyl by means of lithium aluminum hydride affords cinnarizine (101). ... 

Scheme 5 Cathodic reduction of cinnamoyl chloride to the corresponding ketene dimer [70b].

Base-catalyzed cyclization of A -benzoyl-a-chloroacetamide is a classical method used to prepare 2-phenyl-4(5//)-oxazolone. Extension of this methodology to the A -aroylcinnamides 35 afforded a series of 5-arylidene analogues 37 albeit in unstated yield (Scheme 6.12). " Thus, acylation of the sodium salt of a benzamide with a cinnamoyl chloride gave the imides 35 that were converted to 36 via a bromination-dehydrobromination sequence. Cyclization to 37 was affected with sodium hydride in 1,2-dimethoxyethane (DME). The authors noted that catalytic reduction of 37 afforded the 5-(arylidene)oxazolidine from which 37 could be regenerated in the presence of air. 

Many examples have been described in the literature where selective transformation of acid chlorides to aldehydes was successful in the presence of other functional groups. Cinnamoyl chloride was transformed to cinnamaldehyde in 54-60% yields over Pd-BaS04 with addition of quinoline-S or thioquinanthrene.263 o-Chloroben-zoyl chloride gave o-chlorobenzaldehyde in 70% yield in reduction over 2% Pd-kie-selguhr in toluene in the presence of quinoline-S.249 Similarly, 4-chloro- and... 

There have been a few reports describing electroreduction of acyl halides. Benzoyl chloride when reduced (Ep = —1.82 V versus Ag/O.IM AgN03) in aprotic media gives good yields (85%) of stilbenediol dibenzoate [111,112]. This seems to be a general reaction for a variety of acyl chlorides [113]. The reduction of cinnamoyl chloride leads to 2,4-dibenzyl-1,3-cyclobutadione [114] ... 

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. ... 

Unsaturated Acids. The formation of olefinic acid azides by the sodium azide procedure appears to be limited only by the availability of the acid chloride. Examples of a,/3-olefinic acid azides prepared by this method are crotonyl, cinnamoyl, and methacrylyl azides. The hydrazide route to the azide is sometimes complicated by ride reactions. The esters of oleic acid and elaidic acid give the respective hydra-zides in good yield under the usual conditions, but severe treatment causes reduction of the unsaturated hydrazides to stearoyl hydrazide. ... 

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