Methylesters

Quaternized esteramines are usually derived from fat or fatty acid that reacts with an alcoholamine to give an intermediate esteramine. The esteramines are then quaternized. A typical reaction scheme for the preparation of a diester quaternary is shown in equation 9 (210), where R is a fatty alkyl group. Reaction occurs at 75—115°C in the presence of sodium methoxide catalyst. Free fatty acids (230) and glycerides (231) can be used in place of the fatty acid methylester. 

Methoxy-3,4,5,6-tetradehydrocorynantheol (286), 3,4,5,6,18,19-Hexade-hydroochropposinine (287), 3,4,5,6-Tetradehydrositsirikine (288), Alstonine (289), the no-name-alkaloid (290) (Mitragyna speciosa) (98T8433), 3,4,5,6-Tetradehydropalicoside (291) and its methylester which were isolated recently from Strychnos mellodora (99P1171), Serpentine (292), and Serpentinine (293) are known representatives of this class of alkaloids. 

The 0 -phenyl-0 -piperidyl-(2)-acetic acid methylester of BP 135° to 137°C under 0.6 mm pressure is obtained in theoretical yield by hydrogenation of 50 g of 0 -phenyl-0 -pyridyl-(2)-acetic acid methylester in glacial acetic acid in the presence of 1 g of platinum catalyst at room temperature, while taking up 6 hydrogen atoms. Reaction with HCI gives the hydrochloride. Resolution of stereoisomers is described in U.S. Patent 2,957,880. 

A mixture of 4.98 g of acetoacetic acid N-benzyl-N-methylaminoethyl ester, 2.3 g of 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)-1,4-dihydropyridlne-3,5-dicarboxylic acid 3-methylester-5- -(N-benzyl-N-methylamino)ethyl ester hydrochloride. The product thus obtained was then crystallized from an acetone mixture, melting point 136°Cto 140°C (decomposed). 

Methyl Nitrate (Methylnitrat or Salpetersaure-methylester in Ger), CH3.0N02 mw 77.04,... 

Fatty acid methylester FAME-C18 300 1.20 — 80-85°C 90-95°C Bleaching of acid and... 

Alkylbenzenes are the commonest organic feedstocks found in the detergent industry, followed by ethoxylated alcohols, primary alcohols, and, Finally, a-olefins. Methylesters have been minimally applied so far. 

Auch die Acyl-malonsaure-diester werden mit Natriumboranat in Methanol zunachst durch die infolge Ester-Spaltung entstehenden Carbonsaure-methylester zu Aldehyden reduziert8 ... 

Die Reaktion wird mit 3 Mol-Aquivalcnten Natriumboranat durchgefiihrt (mit 1,5 Mol-Aquivalenten crhalt man Carbonsaurc-methylester, mit 11,5 Mol-Aquivalenten Alkohole s.a. S. 196). (2-Chlor-benzoyl)-malon-saure-diathylester wird nicht angegriffen1. 

Bei der Reduktion von Phenylessigsaure-methylester in Tetrahydrofuran wird neben 74% d.Th. 2-Phenyl-athanol auch wenig 2,4-Diphenyl-butandiol-(l,3) erhalten (s.a.S. 148)1. 

Dagegen wird 3-Chlor-phthalsaure-2-methylester zu 3-Chlor-l,2-bis-[hydroxyme-thyl]-benzol (85% d.Th.) reduziert. 

Analog erhalt man aus 3-Acetoxy-phthalsaure-2-methylester mit 0,13 Mol Lithiumala-nat 4-Hydroxy-phthalid (68% d.Th. F 252—254°). 

ZimtalkohoF Unter Riihren wird in einer Suspension von 0,7 g (21 mMol) Lithiumalanat in 45 ml abs. Benzol unter Stickstoff 2,9 g (20 mMol) Zimtsaure-methylester gegeben. Man riihrt 14,5 Stdn. bei 59-60°, kiihlt ab, ver-setzt mit 5 ml Methanol, 2 ml Wasser und 25 ml 5"/niger Salzsaure. extrahiert die waBr. Phase mit 25 ml Chloroform, trocknet und dampft die Solventicn ab Ausbeute 1,95 g (73°/, d.Th.) F 34-35°. 

Phenyl-propiolsaure-methylester wird mit der thcor. Menge des Reduktionsmit-... 

Die Reduktion von Acylamino-carbonsaure-estern mit Diboran ist strukturabhangig. So erhalt manz. B. aus Hippursaure-methylester neben 5nl02-Benzylamino-athanol 11% Benzylamino-essigsdure-methylester8 ... 

Dithiokohlensaure-S-methylester lassen sich mit Tributyl-zinnhydrid zu den entspre-chenden Kohlenwasserstoffen reduzieren2 ... 

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