Carboxylic acid imides methyl esters

C20H27NO4 58115-88-1) see Butorphanol hexahy dro-1 -methyMH-azepin-4-one (C7H13NO 1859-33-2) see Azelastine (3S-trflns)-hexahydro-2-phenyl-l /-pyrroloLl,2-c]imid-azoIe-3-carboxylic acid methyl ester (C14H1KN2O2) see Troglitazone hexahydro-l-(2-propenyl)<4i/-azepin-4-one (CyHi NO) see Talipcxole... 

For the synthesis of (69), the enol ether (71) from the indanone (70) was carboxylated with COa-n-butyl-Iithium in THF at —70 C to yield (72). The methyl ester (73) was converted into (75) via the maleic anhydride adduct (74), essentially as described in earlier work. Lithium aluminium hydride reduction followed by oxidation with dicyclohexylcarbodi-imide afforded the aldehyde (76). This was condensed with excess (77) to yield a mixture of the diastereomers (78). Oxidation with chromium trioxide-pyridine in methylene dichloride gave (79), which could be converted into the diketone (80) by treatment with excess benzenesulphonylazide. The diketo-lactam (81) was prepared from (80) as described for the synthesis of the analogous intermediate used in the synthesis of napelline. Reduction of (81) with lithium tri-t butoxyaluminohydride gave the desired dihydroxy-lactam (82). Methylation of (82) with methyl iodide-sodium hydride gave (83). Reduction of this lactam to the amine (84) with lithium aluminium hydride, followed by oxidation with potassium permanganate in acetic acid, gave (69). 

Oxazolines are formed directly from the reaction of carboxylic acids with 2-ami-no-2-methyl-l-propanol in refluxing toluene but a two-step procedure involving reaction of 2-amino-2-methyl-l-propanol with an acid chloride followed by treatment of the resultant amide with excess thionyl chloride as a dehydrating agent is generally preferred (Scheme 2.128].2 o 26i Alternatives include reaction of dimethylaziridine with a carboxylic acid in the presence of dicyclohexylcarbo-diimide to form the N-acylaziridine followed by acid-catalysed rearrange-ment or reaction of an orthoester, or an imidate ester, with an amino alcohol as illustrated by the conversion of 129.1 to 1293 [Scheme 2.129). ... 

An asymmetric s)mthesis of 5-isopropyloxazoline-4-carboxylic acid methyl ester (164) was performed through the ring expansion on N-acylaziridine (163). The synthesis started from 4-methylpentenoyl imidate 161 that underwent 1,4-addition of 0-benzylhydroxylamine. Ring closure, activation of the aziridine and final ring expansion catalysed by BF3.Et20 afforded the desired compound <01TA563>. 

Radical substitution of the hydrogen from the methyl groups PHj OH,X Kl( -HY CH3 X CH, hc=ch X-Y = Br-Br,C1-C1 (12) RS0.-C1 (13) I 1 ( ) Halogenation, sulfonation, binding of maleric anhydride group, unsaturated carboxyl acids, amides, imides, esters, epoxides, amines, alcohol can be used Product of (12) is precursor for PCMs, that of (13) for direct PCMs. 

In general, the PET decarboxylation of carboxylic acids exhibits low product selectivity, due to the subsequent radical coupling in solution however, the PET reaction between potassium propionate and the methyl ester of N-methyltrimellitic acid imide is highly regioselective to the para-addition product. This contrasts with other intramolecular and intermolecular PET reactions of quinolinic acid imides, which do not show a high degree of regioselectivity (Scheme S)." ... 

Substituted indoles are of biological interest and are not readily synthesized by conventional methods of indole chemistry. Annulation of a nuclear methyl and an a-ethoxyimine (or an imidate) under basic conditions is a promising procedure. The pyridine oxide ester (87.1) may be converted in high yields into two kinds of pyrrole carboxylic ester the potassium salt of the imidate, on heating in DMF, gives the 3-(2-oxocarboxylate) whereas dilute mineral acid leads to the 2-carboxylate ester. 

The presence of one imide function and one asymmetric center appears to suffice for the separation of N-acyl-a-amino acid esters, a-methyl-a-amino acid esters and a-methyl and a-phenyl carboxylic esters [121. An example of this type of stationary phase is as follows. 

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