Tartaric acid, condensation

The purified commercial di-n-butyl d-tartrate, m.p. 22°, may be used. It may be prepared by using the procedure described under i o-propyl lactate (Section 111,102). Place a mixture of 75 g. of d-tartaric acid, 10 g. of Zeo-Karb 225/H, 110 g. (136 ml.) of redistilled n-butyl alcohol and 150 ml. of sodium-dried benzene in a 1-litre three-necked flask equipped with a mercury-sealed stirrer, a double surface condenser and an automatic water separator (see Fig. Ill, 126,1). Reflux the mixture with stirring for 10 hours about 21 ml. of water collect in the water separator. FUter off the ion-exchange resin at the pump and wash it with two 30-40 ml. portions of hot benzene. Wash the combined filtrate and washings with two 75 ml. portions of saturated sodium bicarbonate solution, followed by lOu ml. of water, and dry over anhydrous magnesium sulphate. Remove the benzene by distillation under reduced pressure (water pump) and finally distil the residue. Collect the di-n-butyl d-tartrate at 150°/1 5 mm. The yield is 90 g. 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

By a modified Bischler-Napieralsky reaction, 6 -nitrophenylaceto-jS-3 4-methylenedioxyphenylethylamide, resulting from the condensation of -3 4-methylenedioxyphenylethylamine with 2-nitrophenylacetyl chloride, was converted into 6 nitro-l-benzyl-6 7-methylenedioxy-3 4-dihydroisoquinoline. The methiodide of the latter was reduced with zinc and hydrochloric acid to 6 -amino-l-benzyl-2-methyl-6 7-methylenedioxy-1 2 3 4-tetrahydro/soquinoline dihydrochloride, which by the Pschorr ring-closure reaction, produced dZ-roemerine (IV, p. 317), m.p. 85-7°. By treatment in succession with d- and Z-tartaric acids, the dZ-base was resolved into Z- and tZ-forms. Synthetic Z-roemerine is dimorphic, m.p. 85-7° and 102°, and has [aju — 79-9° (EtOH), these constants being in good agreement with those of the natural base. 

Tile tartaric acid is finely powdered and mi.Ked with half the above quantity (80 c.c.) of absolute alcohol. The mixture is heated on the water-bath with upright condenser until dissolved. The flask is immersed in cold water, and the well-cooled solution saturated with dry hydrochloric acid gas (prepared in the usual way by dropping cone, sulphuric acid into cone, hydiochloric acid, see Fig. 65, p. 93). After standing for an... 

Boil the tartaric acid and caustic soda solution for three hours in a round flask (I litre), or preferably in a tin bottle furnished with reflu. condenser. The use of a tin vessel obviates certain clitli-cultiesof filtration which the solution of the silica by the action of the alkali on the glass entails. The liquid, after boilinjg, is carefully neutralised with cone, hydrochloric acid (it is acl is-able to remove a little of the solution beforehand in case overshooting the mark) and an excess of calcium chloride solution is added to the hot liquid. The mixture is left overni hl. and the calcium salts filtered off at the pump, washed with water, and well pressed. 

Unequivocal syntheses of cis- and mns-(i -decahydroquinoxalincs have been achieved by lithium aluminum hydride reduction of the corresponding cis- and trans-decahydroquinoxaIin-2-ones. The latter compounds were prepared by condensation of chloroacetic acid and cis- and trans-1,2-diaminocyclohexane, respectively. The resolution of frans-dUdecahydroquinoxaline was effected by use of first dibenzoyl-cZ-tartaric acid and then of dibenzoyl- -tartaric acid. "" (C/. p. 215.)... 

The synthesis of porphyrins from dipyrrylmethenes was first developed by Fischer42 and his collaborators. Different variants of this method are available. For the preparation of centrosym-metric porphyrins 7, the self-condensation of 5-bromo-5 -methyldipyrrylmethene hydrobromides or perbromides 6 in organic acid melts like succinic acid, tartaric acid or formic acid at temperatures up to 200 °C can be used. 

The aqueous hydrazide solution is evaporated from a tared 2000 ml flask on an efficient rotary evaporator, using a bath temperature of 40° and an ice-cooled condenser the 3000 ml siphon flask assembly is used as storage for the vacuum feed. The weight of the crude hydrazide so obtained is determined, it is dissolved in about 170 ml 1 N tartaric acid, the aqueous solution washed with three 30 ml portions ether, made alkaline with 190 ml 1 N ammonium hydroxide, and exhaustively extracted with successive portions of chloroform, the first two portions being 100 ml each, the following 50 ml. 

In 1884, H.J. Ziegler first used pyrazolones as coupling components. In an attempt to find a new dye by synthesizing a colored osazone from phenyl hydrazine-4-sulfonic acid and dioxo tartaric acid, he obtained yellow tartrazine by condensation ... 

B. Mono(2,6-dimethoxybenzoyl)tartaric acid. In a 250-mL, three-necked, round-bottomed flask, equipped with a nitrogen inlet, a reflux condenser and a magnetic stirring bar are placed 6.1 g (18.5 mmol) of dibenzyl tartrate, 100 mL of dry dichloromethane, 4 mL (28.8 mmol) of triethylamine and 50 mg (0.4 mmol) of 4-(dimethylamino)pyridine. The stirred mixture is cooled to 0°C 3.65 g (18.2 mmol) of 2,6-dimethoxybenozyl chloride (Note 3) is added portion-wise over 1 hr. The reaction mixture is then warmed to room temperature and refluxed for 12 to 18 hr (the reaction is easily monitored by TLC). The reaction mixture is then allowed to cool down to room temperature and poured in 100 mL of water, The aqueous phase is extracted with 2 x 75 mL of dichloromethane. The organic phases are combined, dried over odium sulfate, filtered and concentrated to give a viscous oil. This is purified by... 

Extension of this condensation to mixed ketones (95) provided further confirmation for the above interpretation. Thus, methyl ethyl ketone and p-chlorophenylbiguanide gave successively the triazine derivatives (CXXVIII) and (CXXIX). The latter (CXXIX) was resolvable into its enantiomers by (+)-tartaric acid this observation supports the six-membered ring structure of (CXXIX) and, because of the very gentle conditions of its isomerisation, that of its isomer (CXXVIII). 

General methods for the preparation of niobium(v) and tantalum(v) complexes have been discussed and better synthetic routes to some known compounds have been described. [Nb(bpha) Cl], [Ta(bpha) Cl], and [NbO(t)3] (where bpha and t are the anions of benzoylphenylhydroxylamine and tropolone, respectively) have been prepared for the first time. NbClj or TaClj in methanol react with Hbpha to form the [M(bpha)4Cl] complexes. An aqueous solution of niobiumfv) which contains tartaric acid to prevent condensation of the hydrolysed metal species affords [NbO(t)3] with tropolone." " ... 

Munoz-Guerra also studied stereoregular polyamides fully based on d- and L-tartaric acid [73]. The bispentachlorophenyl esters of both 2,3-di-(9-methyl-tartaric acids (22 and 23) were condensed with (2S, 3S )-2,3-dimethoxy-l,4-butanediamine (41) to obtain optically active (PTA-LL) and racemic (PTA-LD) polytartaramides. Fiber-oriented and powder X-ray studies of these polyamides demonstrated that PTA-LL crystallized in an orthorhombic lattice, whereas PTA-LD seemed to adopt a tricUnic structure. In both cases, the polymeric chain appears to be in a folded conformation more contracted than in the common y form of conventional nylons. 

Fulcrand, H. et al., An oxidized tartaric acid residue as a new bridge potentially competing with acetaldehyde in flavan-3-ol condensation. Phytochemistry 46, 223, 1997. 

Cinnamic acids may condense with molecules other than quinic acid, including rosmarinic, malic and tartaric acid, aromatic amino acids, choline, mono- and polysaccharides, glycerol, myo-inositol, and different glycosides (anthocyanins, flavonols and diterpenes) [13]. 

An intimate mixture of 600 g. of finely powdered freshly fused potassium acid sulfate and 400 g. of powdered tartaric acid, prepared by grinding them together in a mortar, is placed in a 3-I. round-bottom Pyrex flask connected with a condenser which is filled with water but does not have any water flowing through it. The mixture is heated by means of an oil bath maintained at a temperature between 210 and 220° until liquid no longer distils over. Some foaming takes place (Note 1), but if fused potassium acid sulfate is used and the temperature of the bath does not rise above 220°, it is not difficult to control. The distillate is then fractionated under reduced pressure. Pyruvic acid passes over at 75-80 725 mm. and the yield is 117-128 g. (50-55 per cent of the theoretical amount). 

Method II.—-The apparatus (Fig. 48) is fitted up, being held in position by a clamp holding the condenser C. In the flask A are placed 150 gms. of tartaric acid (or other acid to be esterified), which need not be specially... 

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