Bis malonates

In a similar reaction the bis-tosylate shown below was to be converted into a bis-malonate derivative. In this cyclic derivative both groups are hold closely together and intramolecular reactions proved to be so much faster than intermolecular substitution under all ex-... 

Several procedures for making glutaric acid have been described in Organic Syntheses starting with trimethylene cyanide (28), methylene bis (malonic acid) (29), y-butyrolactone (30), and dihydropyran (31). Oxidation of cyclopentane with air at 140° and 2.7 MPa (400 psi) gives cyclopentanone and cyclopentanol, which when oxidized further with nitric acid at 65—75° gives mixtures of glutaric acid and succinic acid (32). 

The complexation of other mixed oxa aza macrocycles has been studied, and protonation and stability constants of the zinc complexes of macrocycles l,4,10,13-tetraoxa-7,16-diazacycloocta-decane-7,16-bis(malonate), the -7-malonate derivative and -7,16-bis(methylacetate) derivative have been determined by potentiometry at a 1 1 ligand-to-metal ratio.730... 

In other work, solution complex formation of the pendant-arm ligands 1,4,10,13-tetraoxoa-7,16-diazacyclooctadecane-7-malonate and 1,4,10,13-tetraoxoa-7,16-diazacyclooctadecane-7,16-bis(malonate) has been investigated with a range of both transition and nontransition metal ions the 1 1 manganese(II) complexes of these species have been reported to show stabilities (log Ai values) of 7.41 and 5.60, respectively, in water (7=0.15, 25°C). 

Several procedures for making glularic acid have been described in Organic Syntheses starting with trimcthylcne cyanide, methylene bis (malonic acid), g-butyrolactone. and dihydropyran. 

Compound 45 was also obtained by a second route. We prepared the bis (tert-butyl ester) ( )-42 by transforming the DB18C6 diol 40 into bis-malonate 41,... 

With the bis-malonate 56 containing a vra-disubstituted DB18C6 tether, the regioselectivity of the macrocyclization of C70 via double Bingel cyclopropanation... 

The dimerization of dimethyl 2-( +-butylsulfanylfluoromethylene) malonate 181 in the presence of phosphorus pentoxide gave the corresponding tetramethyl-l,3-dithietan-2,4-diylidene bis-malonate 182 in 12% yield (Equation 30)... 

Scheme 1.3. General synthetic scheme for the regio- and stereoselective macrocyclization of Cgo by Bingel addition of tethered bis-malonates.

Figure 1.16. Macrocyclic bis-malonate adducts of Cgo including planar chiral units (( )-35-( )-38).

Mercury bis-malonic methyl ester, Hg[CH(COOMe)2]2-—Methyl malonate (36 grams, 2jmols.), with 25 grams of mercuric oxide (1 mol.) and 50 c.c. of water, are shaken on a machine at 37 C., in the absence of light. After twelve hours a white body having the above composition separates out. It is soluble in cold chloroform and sparingly in alcohol, acetone, or ethyl acetate. It sinters at 125 C. and melts at 127 C. (corr.). Saponification with 4 mols. of Normal alkali, and acidification with dilute sulphuric acid, gives an almost quantitative yield of tlie anhydride of hydroxymercuri-acetic acid. 

Mono- and bis-malonic ester derivatives of 1,3,5-triazine 240 and 241 were studied in various solvents by UV and 111 NMR spectroscopy. The enamine structures as shown predominate in CHC13, dioxane, MeOH, and H20 however, a small amount of the enolate was observed for 241 in acetonitrile and a larger amount in DMSO, DMF and cyclohexylamine. Approximately 33% of 241 exists in the enol form in CDC13/DMSO-4j (1 1) at 0 °C. In a basic solvent, 241 exists as a tautomeric mixture of the enamine form and resonance-stabilized enolate ions (75JHC295). 

One of the first examples of a cycUzation to form a nine-membered ring is that reported by Ali-Zade and Arbuzov <43MI 927-oi>. The reaction of the bis-malonate (152), as its magnesium salt, with bis(bromoethyl)ether afforded the oxonane (153) (Equation (9)). 

Intellectual property assigned to Bayer covers benzylidene malonates and benzylidene bis-malonates [66], and includes the use of this type of stabiliser in the manufacture of polyesters [67]. It is likely... 

Allied Signal Incorporated [87] have patented cinnamamides of the general structure Ph[NH-(C=0)-C(CN)=CPh2]2, and have observed that these are especially effective stabilisers for aromatic polyesters. Clariant have noted that a combination of benzylidene bis-malonates with hindered amine light stabilisers showed excellent synergism in UV-stabilising polyalkylene terephthalates [88]. 

Hostavin B-CAP from Clariant is a new UV stabiliser for polycarbonate and PET, based on a benzylidene-bis-malonate type UV absorber. It has good absorption in the high-energy range of the UV spectrum, and reduces yellowing. It does not interact with residual metal ions, and therefore does not affect either the colour or transparency of the polymer. Clariant recommends combining this UV absorber with other stabilisers for the long-term protection of polycarbonate and PET. 

Weleh obtained methylene-bis-malonic ester in better than. 90 per c-ent i ield by reacting paraformaldehyde and malonic ester in, the presence of aicohdic potassium hydroxide, which was neutralijsed with alcoholic hydrogen chloride before isolating the product by distillation. 

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