P-Aminocrotonate

Displacement of activated chlorine atoms also proceeds with certain types of organic compounds, but only in the presence of Lewis acid catalysts. Particular examples include epoxides, polyhydric alcohols, trialkylphosphites (12), and P-aminocrotonates (13). These additives are commonly used in conjunction with metallic stabilizers to provide complete, high performance, commercial stabilizer packages. 

The reaction of C2S2 with 2-aminopyridine and /V-pbenylbensamidine yields the higher condensed derivatives C2S2 also reacts with p-aminocrotonate to yield H2NC(CH2)=C(COOC2H2)]2S (7). 

Condensation of the TV-substituted p-aminocrotonic acid ester 15 with p-benzoquinone (4) has been successfully carried out to furnish the 5-hydroxyindole 29 when the substituent R on the nitrogen of the aminocrotonic acid ester was methyl, ethyl, -propyl, isopropyl, or -butyl, -hexyl, p-cyanoethyl, p-hydroxyethyl, carbethoxymethyl, benzyl, phenyl, o-tolyl, dimethylaminopropyl, y-hydroxypropyl etc ... 

Random incorporation of two different acetoacetates can also be avoided by converting one of the acetoacetates to a derivative which carries the future pyridine nitrogen. For example, treatment of ethyl acetoacetate with ammonia gives the corresponding P-aminocrotonate 32. The aldehyde (34) required for preparation of such an unsymmetrical compound is prepared by reaction of the product from direct metallation of 33 with dimethylformamide. Condensation of that aldehyde with methyl acetoacetate and the p-aminocrotonate from isopropyl acetoacetate leads to isradipine (35) [9]. The same aldehyde with ethyl acetoacetate and the P-aminocrotonate from ethyl acetoacetate gives darodipine (36) [10]. In much the same vein, condensation of the ben-zaldehyde 37 with methyl acetoacetate and its P-aminocrotonate derivative affords riodipine (38) [11]. 

Bagley et al. performed a number of pyrimidine and pyridine syntheses by condensing an inone—generated in situ by oxidation of a propargylic alcohol with IBX with amidines and p-aminocrotonate.108... 

In 5 ml of isopropyl alcohol were dissolved 1.5 g (0.01 mole) of 3-nitrobenzaldehyde, 2.6 g (0.01 mole) of l-benzyl-3-acetoacetyloxypyrrolidine, and 1.3 g (0.01 mole) of p-aminocrotonic acid methyl ester and then the solution was refluxed for 8 hours. The solvent was distilled off under reduced pressure, the residue obtained was dissolved in a small amount of chloroform, and the solution was applied to silica gel column chromatography (column diameter 1.5 cm, height 20 cm, and about 200 ml of chloroform was used as the eluent). The eluates were collected and concentrated to give 3.4 g of oily... 

Acetoacetic acid N-benzyl-N-methylaminoethyl ester p-Aminocrotonic acid methyl ester m-Nitrobenzaldehyde... 

A mixture of 4.98 g of acetoacetic acid N-benzyl-N-methylaminoethyl ester, 2.3 g of p-aminocrotonic acid methyl ester, and 3 g of m-nitrobenzaldehyde was stirred for 6 hours at 100°C in an oil bath. The reaction mixture was subjected to a silica gel column chromatography (diameter 4 cm and height 25 cm) and then eluted with a 20 1 mixture of chloroform and acetone. The effluent containing the subject product was concentrated and checked by thin layer chromatography. The powdery product thus obtained was dissolved in acetone and after adjusting the solution with an ethanol solution saturated with hydrogen chloride to pH 1-2, the solution was concentrated to provide 2 g of 2,6-dimethyl-4-(3 -nitrophenyl)l,4-dihydropyridine-3,5-dicarboxylic acid 3-methylester-5-p-(N-benzyl-N-methylamino)ethyl ester hydrochloride. The product thus obtained was then crystallized from an acetone mixture, melting point 136°C to 140°C (decomposed). 

Nitrobenzylideneacetoacetic acid methyl ester p-Aminocrotonic acid isopropyl ester... 

Senary, E. Synthesis of Pyridine Derivatives from Dichioroether and P-Aminocrotonic Ester. Ber. 1911,44, 489-493. 

NENITZESCU 5-Hydroxyindole Synthesis 5-Hydroxyindole synthesis from quinones and p-aminocrotonates (see 1st edition). 

With the exception of diaryl ketones, all aldehydes and ketones undergo the 4CC as the carbonyl component (4). Note that the derivatives of the a-oxocarboxylic acids react very well as the carbonyl components (4),2944 whereas the derivatives of the P-oxocarboxylic acids may form the resonance-stabilized derivatives of P-aminoacrylic acid, such as ethyl P-aminocrotonate (45), which can even be used as the amine component (43) of the Ugi reaction.45... 

Figure 5. Zinc chloride formation in the sheets of rigid PVC heated in a stove at 180°C under nitrogen atmosphere ana in the presence of a secondary stabilizer. (1) a-pnenylindole, 2.13 phr (2) epoxidizea soya bean oil, 5.53 phr (3) epoxidized soya bean oil, 16 phr (4) bu-tanediol-P-aminocrotonate, 2.7 phr.

In modifications of the Hantzsch synthesis [65], P-enaminones replace one molecule of the P-dicarbonyl compound, and enones undergo cyclocondensation with P-enaminones or 1,5-dicarbonyl compounds with NH3. Thus, for instance, as an alternative to the classical synthesis (2 mol acetoacetate, benzaldehyde and NH3), the l,4-dihydropyridine-3,5-dicarboxylate 171 is obtained from acetoacetate, benzaldehyde and p-aminocrotonate (1 1 1), as well as from benzylidene acetoacetate and aminocrotonate (1 1). 

A new pyridone synthesis was developed to form the basis of the second synthesis (Scheme 27) to be announced. This new heterocyclic method involves, in essence, the interaction of a 1,3-dialkoxycarbonylallene with a P-aminocrotonate [in the present context, (95)] or mono-enamine of a 1,3-dicarbonyl... 

From P-Aminocrotonates Type C). A one-step synthesis of glycosylamino-isothiazoles (5) involves the reaction between a glycosyl isothiocyanate (RNCS) and MeC(NH2)=CHC02Et. ... 

Production of ampicillin via methyl N( a-carboxy-benzyl)-P-aminocrotonate is illustrated. The process for the preparation of the g] o ted a-phenylglycine has been patented and can be summarized as follows ... 

In recent years, metal-free stabilizer systems have been developed because of environmental concerns of traditional lead and tin stabilizers. Chemically regarded nitrogen-based molecules are used, for example, P-aminocrotonates, dihydropyrimidines [15], trialkanolamines, as well as their reaction products and salts, for example, the perchlorate salt [16], etc. (Fig. 11.11). Owing to their good compatibility with other stabilizers, organic-based stabilizers are predestinated to be used in PVC recycling in case restabilization is needed [17]. 

N-l Substituted DHPMs 22 (Scheme 9) have also been obtained through a two-step regioselective cyclocondensation of a-chlorobenzyl isocyanates with ethyl N-substituted-p-aminocrotonates 21 (R = alkyl/ aryl) (06SL375, 07S835). This methodology is further extended to synthesize N1-C6 linked bicyclic DHPM derivatives (07S835). 

The Nenitzescu indole synthesis is the formation of a 5-hydroxylindole from the condensation of p-benzoquinone and P-aminocrotonate. 

In this modification of the Feist-Benary synthesis of furans (section 15.13.1.4) ammonia, or a primary amine, is incorporated. The pyrrole is probably formed by initial interaction of ammonia (an amine) with the P-ketoester, the resulting p-aminocrotonate then being alkylated by the halo-ketone or -aldehyde. ... 

Dioctyltin dilaurate Dioctyltin maleate Dioctyltin p-mercaptopropionate N,N -Diphenylthiourea Epoxy, bisphenol A Lauryl p-aminocrotonate Lead carbonate ... 

Lead carbonate basic Lead 2-ethylhexoate Lead phthalate, dibasic Lead stearate, dibasic Lead sulfate, basic Magnesium/aluminum/hydroxide/carbonate Methyltin tris (isooctylthioglycollate) Methyltin tris (2-mercaptoethyl oleate) p-Nonyl phenol (n-Octyl) tin S,S, S" tris (isooctyl mercaptoacetate) 2-Phenyl indole Thiodiglycol di-P-aminocrotonate Tris (nonyiphenyi) phosphite Tris (tridecyl) phosphite Zinc laurate Zinc stearate... 

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