N-methylanthranilate

Both these acids are colourless, but the spots of each acid on a filter-paper strip show up in ultraviolet light as intense blue fluorescent zones. They can also be detected, but considerably less sensitively, by spraying with ethanolic ferric chloride solution, which gives with N-methylanthranilic acid a purple-brown coloration. 

N-Methylanthranilic acid is very readily prepared (p. 222). Prepare a sample of this acid and recr> stallise it 2 or 3 times from ethanol until it has m.p. 177" and is pure . 

Record the Rp values of the two acids under the above conditions the anthranilic and the N-methylanthranilic acid should have Rp values of 0-28 and 0 55 respectively. 

In the sjmthesis of evodiamine effected by Asahina and Ohta,i N-methylanthranilic acid was converted by ethyl chloroformate into N-methylisatoic anhydride, which, on treatment with 3- -aminoethylindole, furnished 3-/3-o-methylaminobenzoylaminoethylindole (III), and this with ethyl orthoformate at 175-180° gave dZ-evodiamine, m.p. 278°, convertible by boiling alcoholic hydrogen chloride into Zsoevodiamine, m.p. 147°, as shown above. 

B-Chloro-N-methylanthranilic acid Bromoethylamine hydrobromide Calcium carbonate Sodium hydroxide Phosphorus oxychioride... 

A) Preparation of 4-Acetyl-7-Chloro-1,2,3,4-Tetrahydro-1-Methyl-5H-1,4-Bemodiazepin-5-one A mixture of 68.5 g (0.37 mol) of 5-chloro-N-methylanthranilic acid, 51 g (0.51 mol) of calcium carbonate, 76 g (0.37 mol) of bromoethylamine hydrobromide and 2.5 liters of water was stirred and heated under reflux for 3 hours. A solution of 23.4 g (0.26 mol) of anhydrous oxalic acid in 250 ml of water was slowly added to the refluxing mixture. The precipitated calcium oxalate was filtered off, and the filtrate adjusted to pH 7 with concentrated ammonium hydroxide. The filtrate was then concentrated to dryness in vacuo and the residue heated on the steam bath with 400 ml of 6 N ethanolic hydrogen chloride until the residue was crystalline. Filtration gave 122 g of N-(aminoethyl)-5-chloro-N-methylanthranilic acid hydrochloride as a solid. 

Two similar syntheses have been reported by Ziegler and co-workers (487) and Kametani et al. (488,489). Reaction of N-methylisatic anhydride (584) with thioacetamide afforded glomerin (60) in 58% yield (487). The other synthetic route is as follows The sulfinamide (585), prepared from N-methylanthranilic anhydride and thionyl chloride, was treated with acetamide and propionamide to afford glomerin (60) and homoglomerin (61), respectively (Scheme 72) (488,489). 

Incorporation of anthranilic acid at the N-terminus instead of /3-alanine, led to the amidine (69). Finally, the cyclol (70) was obtained in 33% yield from the analog having N-methylanthranilic acid this reaction also gave the 10-membered cyclotripeptide in 17% yield (84TL5201). 

Daidone and co-workers cyclized the diazonium salt derived from N-pyrazolylbenzamide 173 to obtain, in addition to other products, a small amount of pyrazolodiazocine, 174 (R = Ph) (80JHC1409). Rahman condensed 3-chloro-4-aryl-1,2,4-triazoles with N-methylanthranilic acid to afford triazoles 175 (R = H, Me R = Me). Conversion of this compound to the acid chloride, followed by cyclization with aluminum chloride,... 

A convenient synthesis of quinazolines has been reported, and has been applied to the synthesis of representative alkaloids of the quinazoline group (Scheme 5).27 The procedure depends on the formation of sulphinamide anhydrides (23) from the reaction of anthranilic acids with thionyl chloride and the generation in situ of the iminoketens (24). Addition of the latter to the imine (25) or to 2-piperidone, for example, afforded alkaloid (27). Arborine (26) was prepared similarly from N-methylanthranilic acid application of the method to the synthesis of rutecarpine is described in Chapter 11. 

Baumert, A., Kuzovkina, N. and Groger, D. (1985) Activation of anthranilic acid and N-methylanthranilic acid by cell-free extracts from Ruta graveolens tissue cultures. 

METHYL-o-ANISIDINE see MGO750 p-METHYL ANISOLE see MGPOOO 9-METHYLANTHRACENE see MGP750 METHYL ANTHRANILATE (FCQ see APJ250 N-METHYLANTHRANILIC ACID, METHYL ESTER see MGQ250... 

Reactions catalyzed by (micro)peroxidases include sulfoxidation, N-demethyl-ation, oxidation, and hydroxylation. A typical example of an interesting N-de-methylation reaction is the conversion of methyl-N-methylanthranilate from citrus into the concord grape topnote N-methylanthranilate (Fig. 7.14). Florse-... 

Italian mandarin oils are characterised by the terpenes limonene (app. 70%) and y-terpinene (app. 20%). Apart from a-sinensal and long-chain saturated aldehydes there is a number of sensorially important unsaturated aldehydes with citrus-like, aldehy-dic, fatty and waxy flavour. Also the potent C-11-hydrocarbons (l,3E,5Z)-undeca-triene, (1,3E,5E,8Z)-, (l,3E,5Z,8Z)-undecatetraene and methyl N-methylanthranilate characterise the typical taste and odour of red mandarin [76]. The latter compound, which also causes the fluorescent character of mandarin oil, is a main constituent of mandarin leaf oils (see Petitgrain oils). 

When compared to Italian mandarin oils, other mandarin [77] or tangerine oils such as Dancy [76] or Murcott tangerine [78] are even more dominated by limonene (app. 95%). Moreover, the composition of the flavour compounds and, therefore, the entire flavour profile, is considerably less complex [76], This is also evident in the rather different content of methyl N-methylanthranilate and a-sinensal. Apart from the... 

The Petitgrain oils of the citrus varieties mandarin (Citrus reticulata Blanco) and lemon (Citrus limon (L.) Burm.) are also commercially available, but to a far lesser extent than for bitter orange. Mandarin Petitgrain oil is characterised by its unique sensory impact, which apart from y-terpinene (20-25%) results from its high content of methyl N-methylanthranilate (40-50%) [106-108]. 

S. Faulhaber (1997) GC/IRMS analysis of mandarin essential oils. 1. 5 Cppg and 5 N, p values of methyl N-methylanthranilate. J. Agric. Food Chem. 4 2579-2583... 

C]Tryptophan gave inactive alkaloids but tritiated 2,4-dihydroxy-quinoline (34) and its N-methyl derivative were incorporated into (47) (0.009 % and 0.020% respectively) an early route had suggested the derivation of what was essentially (34) from tryptophan. Radioisotope dilution showed the presence of both these quinoline precursors together with iV-acetyl- and N-methyl-anthranilic acid in A. baueri. A satisfactory incorporation of N-methylanthranilic acid into (47) was found in Evodia xanthoxyloides, and this, together with its natural occurrence, indicates that early methylation may be important in the biosynthesis of acridone alkaloids. 

Watanabe et al. (84CPB1264) have reported a one-step synthesis of acronycine 208. Lithium methyl(2-methoxycarbonyl)phenyl amide 258 generated from methyl N-methylanthranilate 257 in situ in the presence of excess lithium cyclohexylamide (LCA), was reacted with 6-bromo-2, 2-dimethyl-7-methoxychromene 259 to produce acronycine 208. A benzyne intermediate 260 is believed to be involved in this reaction (Scheme 44). 

There are a few tetra- and pentacyclic analogues. Benzo analogues of 245 were prepared from pyridine-2,3-dicarboxylic acid anhydride and a tetralin derivative under conditions of the Friedel-Crafts reaction (85JCR(S)338). Pentacyclic compounds 258 (R = H or Me) were prepared from the bis adduct of anthranilic (or N-methylanthranilic) acid to 1,4-benzoquinone, followed by cyclization in concentrated sulfuric acid (55JCS4440 66CB1991). 6-Methylquinoline-5,8-dione dimerized in the presence of ethanolic IV-methyl-cyclohexylamine to 259 in very low yield and the dimerization is interpreted as two base-catalyzed addition reactions and three oxidation steps (71JCS(C)1253). 

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