Methoxybenzoates

Benzyl indole-5-carboxylate Methyl 4-(bromomethyl)-3- 45 methoxybenzoate, DMF, 80°C [9]... 

A solution of benzyl indole-5-carboxylate(1.0g, 3.98 mmol) and methyl 4-(bro-momethyl)-3-methoxybenzoate (2.06 g, 7.97 mmol) in dry DMF (10 ml) was heated at 80°C for 24 h. The reaction solution was cooled, poured into water (100 ml) and the product extracted with EtOAc (3 x 75 ml). The extract was washed with water and brine and dried over MgSO, . The product was obtained by evaporation of the solvent and purified by chromatography on silica gel using 1 4 EtOAc/hexane for elution. The yield was 1.11 g (32%) and some of the indole (30%) was recovered unreacted. 

Ethyl indole-2-carboxylate 4-Methoxybenzoic acid, TFAA, H3PO4 74 [11]... 

Ewins has synthesised both substances from m-methoxybenzoic acid, which on nitration gave 2-nitro-3-methoxybenzoic acid, and this, on reduction and treatment with methyl iodide, yielded damasceninic acid, which, by esterification with methyl alcohol, furnished damascenine. Kaufmann and Rothlen found that the additive product of 8-methoxy-quinoline and methyl sulphate, on oxidation with permanganate, yields formyldamasceninic acid, MeO. CgH3(NMe. CHO). COOH, which can be transformed into damasceninic acid by warming with dilute hydrochloric acid. ... 

Results of the sulfur tetrafluoride fluorination of benzenecarboxylic acids strongly depend on the nature of a benzene ring substituent Benzoic, toluic, and particularly p-methoxybenzoic acids give poor yields of the respective benzotri-... 

The benzoate ester is one of the more common esters used to protect alcohols. Benzoates are less readily hydrolyzed than acetates, and the tendency for benzoate migration to adjacent hydroxyls, in contrast to that of acetates, is not nearly as strong, but they can be forced to migrate to a thermodynamically more stable position. The p-methoxybenzoate is even less prone to migrate than the benzoate. Migration from a secondary to a primary alcohol has also been induced with AgN03, KF, Pyr, H2O at 100°. ... 

Nitration of quinindoline gave the expected 9-nitro derivative (261). A single mononitro compound was formed from the 3,4-dihydro-jS-carboline, harmaline this was 6-nitroharmaline, since on oxidation it yielded 3-nitro-4-methoxybenzoic acid. 

Suitable substrates for the Hunsdiecker reaction are first of all aliphatic carboxylates. Aromatic carboxylates do not react uniformly. Silver benzoates with electron-withdrawing substituents react to the corresponding bromobenzenes, while electron-donating substituents can give rise to formation of products where an aromatic hydrogen is replaced by bromine. For example the silver /)-methoxybenzoate 6 is converted to 3-bromo-4-methoxybenzoic acid 7 in good yield ... 

It has been prepared synthetically by Ewins in the following manner Meta-oxybenzoic acid is converted with the aid of dimethyl sulphate into m-methoxybenzoic acid, which is then nitrated, and from the nitration products 2-nitro-3-methoxybenzoic acid is separated. This is reduced to 2-amino-3-methoxybenzoic acid which on heating with methyl iodide, yields 2-methylamino-3-methoxybenzoic acid. On warming this with freshly precipitated silver chloride it yields damascenine hydrochloride. 

The relationship between 20 and reserpine (1) is close like reserpine, intermediate 20 possesses the linear chain of all five rings and all six stereocenters. With the exception of the 3,4,5-tri-methoxybenzoate grouping, 20 differs from reserpine (1) in one very important respect the orientation of the ring C methine hydrogen at C-3 in 20 with respect to the molecular plane is opposite to that found in reserpine. Intermediate 20 is a reserpate stereoisomer, epimeric at position 3, and its identity was secured by comparison of its infrared spectrum with that of a sample of (-)-methyl-O-acetyl-isoreserpate, a derivative of reserpine itself.9 Intermediate 20 is produced by the addition of hydride to the more accessible convex face of 19, and it rests comfortably in a conformation that allows all of the large groups attached to the D/E ring skeleton to be equatorially disposed. 

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