Ethyl cinnamate preparation

Ethyl cinnamate may also be prepared by the esterification of cinnamic acid. The pure compound boils at 127°/6 mm. 

It is prepared by treating ethyl cinnamate with peracetic acid [212] or by condensation of benzaldehyde with ethyl chloroacetate (in the above Darzens reaction, R = H). The glycidate is used as a long-lasting fragrance material for creating harmonic, fruity notes in household and fine fragrances. 

Ethyl <2,/3-dibromo-/3-phenylpropionate is prepared by adding bromine to ethyl cinnamate.1... 

Scheme 2 shows Rapoport s synthesis [15]. The cinnamic acid derivative 3 prepared from m-methoxy benzaldehyde [20] was ethylated by diethyl sulfate to give ethyl cinnamate derivative 4, followed by Michael addition with ethyl cyanoacetate to afford compound 5. Compound 5 was converted to lactam 6 by the reduction of the cyano group and subsequent cyclization. Selective reduction of the lactam moiety of 6 was achieved by treatment with trimethy-loxonium fluorob orate followed by sodium borohydride reduction. Amine 8 was obtained by the reductive methylation of amine 7. Amine 8 was converted to compound 9 by methylene lactam rearrangement [21], followed by selenium dioxide oxidation to provide compound 10. Allylic rearrangement of compound 10 and subsequent hydrolysis gave compound 12. The construction of the decahydroisoquinoline structure began with compound 12,... 

Cognate preparations. Phenylpropynoic acid. Place a solution of 88 g (84 ml, 0.5 mol) of ethyl cinnamate (Expt 6.137) in 50 ml of carbon tetrachloride in a 500-ml round-bottomed flask. Immerse the flask in ice and add 80 g (25.5 ml, 0.5 mol) of bromine from a separatory funnel slowly with frequent shaking. The halogen will disappear rapidly at first, but more slowly towards the end of the reaction no hydrogen bromide is evolved and the time of the addition is about 20-25 minutes. Allow the mixture to stand for 1 hour, pour the solution into a large evaporating dish and permit the excess of bromine and the carbon tetrachloride to evaporate spontaneously in the fume cupboard. The crude ethyl 2,3-dibromo-3-phenylpropanoate will remain as a solid cake this... 

Certain aromatic and heterocyclic olefinic esters ate best prepared by condensation of ethyl acetate and aromatic aldehydes by sodium sand (Claisen). Benzaldehyde in this reaction gives ethyl cinnamate, C,HsCH=CHC03C,H5 (74%). p-Methylbenzaldehyde, furfural, furylactolein, and 2-thiophenecarboxaldehyde have been condensed in a similar manner. 

Dimerization.- A reinvestigation of the dimerization of (124) in the solid phase has identified (125) as the product. The irradiation of microcrystalline methyl cinnamate (126) affords a complex mixture of products. However, the preparation of crystalline complexes of this ester with boron trifluoride or stannic chloride followed by irradiation affords high yields of the a-truxillate dimer (127). Ethyl cinnamate also forms complexes with the same reagents but irradiation of these crystalline complexes affords a mixture of dimers in low... 

Wittig reactions. Ethylene oxide can be used as the base for generation of Wittig reagents from phosphonium salts. It is often not necessary to prepare the salts thus a mixture of ethylene oxide, triphenylphosphine, and ethyl bromoacetate reacts with benzaldehyde at 25° to give ethyl cinnamate (91% yield, trans.cis = 93 7).3... 

The synthesis of pyridazine derivatives from hydrazones includes the thermal cyclization of 2-arylhydrazono-3-oxo-5-phenyl-4-pentenenitriles (readily obtained from ethyl cinnamate by condensation with acetonitrile followed by Japp-Klingemann type reactions) to l-aryl-3-cyano-6-phenyl-5,6-dihydro-4(l//)-pyridazinones (Scheme 85) <86JHC93>, and base-induced cyclization of a hydrazone of a 4-chloro-l-arylbutan-l-one to prepare a 2,3,4,5-tetrahydropyridazine (Scheme 85) <88JHC1543>. An earlier route to 6-carboxy-5-hydroxy-2-phenyl-3(2//)-pyridazinone via condensation of benzenediazonium chloride and dimethyl acetonedicarboxylate has been adapted to give a series of aryl derivatives either as esters (by thermal cyclization) or as acids (by cyclization with hydroxide). Both cyclizations proceed in high overall yield (Scheme 86) and decarboxylation of the acids also proceeds in high yield <89JHC169>. 

Methoxy-4,5-methylenedioxycinnamyl alcohol (46) (ref. 16, 53) and 3,4,5-trimethoxyphenylpropiolic acid (49) (ref. 54) were prepared through the scheme shown in Chart 11. 3-Methoxy-4,5-methylenedioxybenzaldehyde (44) (ref. 55) obtained from vanillin via 5-iodovanillin and 5-hydroxyvanillin was converted to the corresponding ethyl cinnamate (4 5) by means of the Horner-Emmons reaction... 

The starting materials, frans-3,4-methylenedioxycinnamyl alcohol (61a) and frans-2-methoxy-3,4-methylenedioxycinnamyl alcohol (61b) were prepared from the corresponding benzaldehyde via substituted ethyl cinnamate by means of the Horner-Emmons reaction and lithium aluminium hydride reduction. Condensation of compound (61 a) or (61 b) with compound (47) gave compound (62a) or (62b), respectively, followed by ring closure to afford compound (63a) or (63b). Intramolecular Diels-Alder reaction of compound (6 2) led to the formation of the aromatized compounds as by-product in both cases. Moreover, in the reaction of... 

Claisen Condensation Preparation of Ethyl Cinnamate and Cinnamic Acid 15 ... 

Cinnamic acid can be readily esterified by the Fischer-Speier method without any risk of the addition of hydrogen chloride at the double bond. Proceed precisely as for the preparation of ethyl benzoate (p. 104), using 20 g. of cinnamic acid and 20 ml. of rectified spirit. When the crude product is poured into water, a sharp separation of the ester is not readily obtained, and hence the addition of about 10 ml. of carbon tetrachloride is particularly desirable. Finally distil off the carbon... 

As with poly(vinyl alcohol), poly(vinyl cinnamate) is prepared by chemical modification of another polymer rather than from monomer . One process is to treat poly(vinyl alcohol) with cinnamoyl chloride and pyridine but this is rather slow. Use of the Schotten Baumann reaction will, however, allow esterification to proceed at a reasonable rate. In one example poly(vinyl alcohol) of degree of polymerisation 1400 and degree of saponification of 95% was dissolved in water. To this was added a concentrated potassium hydroxide solution and then cinnamoyl chloride in methyl ethyl ketone. The product was, in effect a vinyl alcohol-vinyl cinnamate copolymer Figure 14.8)... 

Phenyl-propyl alcohol, CgH. CHj. CH.2. CHj. OH, is the next highest homologue of phenyl-ethyl alcohol, and is also known as hydro-cinnamyl alcohol. Like the last described bodies it has been known for many years, its first preparation being described in the Aivnalen (188, 202). It occurs as a cinnamic acid ester in storax, and as an acetic ester in cassia oil. It is prepared synthetically by the reduction of cinnamyl alcohol with sodium amalgam and water, or by the reduction of cinnamic or benzyl acetic esters with sodium and absolute alcohol. It has the following characters —... 

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