2-Methoxycarbonyl-6,7-dihydro

IH-Azepine, 1-methoxy carbonyl-cycloaddition reactions, 7, 522 with nitrosobenzene, 7, 520 tricarbonyliron complex acylation, 7, 512-513 conformation, 7, 494 tricarbonylruthenium complex cycloaddition reactions, 7, 520 1 H-Azepine, l-methoxycarbonyl-6,7-dihydro-synthesis, 7, 507... 

H-Azepine, 2,6,7-tri(methoxycarbonyl)-ring inversion, 7, 499 Azepine-1-carboxylic acid tricarbonylruthenium complexes, 7, 523 1 H-Azepine-2,3-dicarboxylic acid, 4,7-dihydro-6-phenyl-diethyl ester synthesis, 7, 539-540 1 H-Azepine-3,6-dicarboxylic acid... 

Alkyl-1,4-dihydropyridines on reaction with peracids undergo either extensive decomposition or biomimetic oxidation to A-alkylpyridinum salts (98JOC10001). However, A-methoxycarbonyl derivatives of 1,4- and 1,2-dihydro-pyridines (74) and (8a) react with m-CPBA to give the methyl tmns-2- 2>-chlorobenzoyloxy)-3-hydroxy-1,2,3,4-tetrahydropyridine-l-carboxylate (75) and methyl rran.s-2-(3-chlorobenzoyloxy)-3-hydroxy-l,2,3,6-tetrahydropyridine-l-carboxylate (76) in 65% and 66% yield, respectively (nonbiomimetic oxidation). The reaction is related to the interaction of peracids with enol ethers and involves the initial formation of an aminoepoxide, which is opened in situ by m-chlorobenzoic acid regio- and stereoselectively (57JA3234, 93JA7593). 

Choice of catalyst and solvent allowed considerable flexibility in hydrogenation of 8. With calcium carbonate in ethanol-pyridine, the sole product was the trans isomer 9, but with barium sulfate in pure pyridine the reaction came to a virtual halt after absorption of 2 equiv of hydrogen and traws-2-[6-cyanohex-2(Z)-enyl]-3-(methoxycarbonyl)cyclopentanone (7) was obtained in 90% yield together with 10% of the dihydro compound. When palladium-on-carbon was used in ethyl acetate, a 1 1 mixture of cis and trans 9 was obtained on exhaustive hydrogenation (S6). It is noteworthy that in preparation of 7 debenzylation took precedence over double-bond saturation. 

Dichloro- and l,2-dibromo-l,2-dihydro-3-benzoxepins are dehalogenated with zinc in methanol to give 3-benzoxepin (6a) in excellent yield.93 A methoxycarbonyl group in the 2-position, however, diminishes the yield of 6b considerably.91... 

Dimcthyl-2-(5-hydroxy-pentyl)-4,5-dihydro-aus 5,5-Dimethyl-2-(4-methoxycarbonyl-butyl)-... 

Only one procedure has been reported recently within this category. Thus 7-chloro-l-methyl-5-phenyl-2,3-dihydro-lH-benzodiazepin-2-one 4-oxide (437) with dimethyl acetylenedicarboxylate in methylene chloride at 20° C for 3 days gave a separable mixmre of the primary tricyclic adduct, dimethyl lO-chloro-6-oxo-llb-phenyl-5,6,7, 1 lb-tetrahydroisoxazolo[2,3-t/] [ l,4]benzodiazepine-1,2-dicarboxylate (438), and its rearrangement product, 6-chloro-4-(2-methoxalyl-2-methoxycarbonyl-l-phenylvinyl)-l-methyl-3,4-dihydro-2(lT0-quinoxalinone (439) each product afforded 6-chloro-l-methyl-2(l//)-quinoxalinone (440) on refluxing in ethanol (see also Section 1.7.13). However, the final quinoxaline (440) was best obtained in 75% yield) by simply heating the initial substrate (437) and dimethyl... 

Ethoxycarbonylmethyl-2(l//)-quinoxalinone (62) gave 3-methoxycarbonyl-methylene-l,4-dimethyl-3,4-dihydro-2(l/ )-quinoxalinone (63) (CH2N2,... 

Amino-7-methoxy-2-methoxycarbonyl-3-phenyl-5,8-quinoxalinequinone 6-Amino-7-methoxy-l-methyl-2-oxo-3-phenyl-1,2-dihydro-5,8-quinoxalinequinone 3-Amino-6-methoxy-8-nitro-2-quinoxalinecarbo-nitrile 1,4-dioxide... 

Reaction of 2-cyanomethylpyridine with iV-(l-aryl-l-chloro-2,2,2-trifluoroethyl)-iV -(4-methylphenyl)carbodiimides, and with (1,1,2,2,2-pentachloro- and l,l-dichloro-2,2,2-trifluoroethyl)isocyanates or A-methoxycarbonyl-l,2,2,2-tetrachloro-, — l-chloro-2,2-trifluoroacetaldehyde imines afforded 3-aryl-4-cyano-l-(4-methylphenyl)imino-3-trifluoromethyl-2,3-dihydro-17/-pyrido[l,2-f]pyrimidines and 4-cyano-3-trichloro-, 4-cyano-3-trifluoro-17/-pyrido[l,2-4pyrimidin-l-ones, respectively <2004CHE47>. Refluxing 2-cyanomethylpyridine and iV-(l-aryl-l-chloro-2,2,2-trifluoroethyl)isocyanates in benzene furnished l-aryl-4-cyano-l-trifluoromethyl-l,2-dihydro-3//-pyrido[l,2-4pyrimidin-3-ones. However, when the solution of the isocyanate was added dropwise to the solution of 2-cyanomethylpyridine, and the reaction mixture was then treated with NEt at room temperature, the isomeric 3-aryl-4-cyano-3-trifluoromethyl-2,3-dihydro-l//-pyr-ido[l,2-dpyrimidin-l-ones were obtained. Reaction of l-(acetyl- and benzoylmethylene)-6,7-dimethoxy-l,2,3,4-tetra-hydroisoquinolines with PhCONCS yielded 1-acetyl-, 1 -benzoyl-9,10-dime thoxy-3-pheny 1-6,7-dihydro-2//-pyrimido[6,l- ]isoquinoline-2-thiones <2003SL2369>. 

Photolytic cleavage (at 320nm) of the substituent at position 1 of 9-cyclopropyl-l-[(4,5-dimethoxy-2-nitrophenyl)-methoxycarbonyl-3-fluoro-2,6-dioxo-l,2-dihydro-6//-pyrido[l,2-tf]pyrimidine-7-carboxylate gave 9-cyclopropyl-3-fluoro-2-hydroxy-6-oxo-6//-pyrido[ 1,2-tf]pyrimidin-7-carboxylate <1995WO95/010519, 1996WO96/039407,... 

Thermal ene reactions of 3-(alk-2-enyl)benzylamino-2-(methoxycarbonyl) acrolein derivatives have been reported to give the substituted 4,5-dihydro-lff-azepines 3 (R = H, Me, Ph, 2-furyl, CC Et) in good yield <00T1299>. 

Heterocycles Both non-aromatic unsaturated heterocycles and heteroaromatic compounds are able to play the role of ethene dipolarophiles in reactions with nitrile oxides. 1,3-Dipolar cycloadditions of various unsaturated oxygen heterocycles are well documented. Thus, 2-furonitrile oxide and its 5-substituted derivatives give isoxazoline adducts, for example, 90, with 2,3- and 2,5-dihydro-furan, 2,3-dihydropyran, l,3-dioxep-5-ene, its 2-methyl- and 2-phenyl-substituted derivatives, 5,6-bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]hept-2-ene, and 1,4-epoxy-l,4-dihydronaphthalene. Regio- and endo-exo stereoselectivities have also been determined (259). 

K. Therefore, the chloro group in compound 124 (M = Si) raises the barrier more than did the methoxycarbonyl group in 125, when the skeleton is 9,10-dihydro-9,10-ethenoanthracene. As expected, when the skeleton was changed from dihydroethenoanthracene to triptycene, the barrier was raised. Thus 9-trimethylsilyl-l,4-dimethoxytriptycene (126) did not show coalescence of the methyl signals, although the solution was heated to 180°C. The barrier to rotation was thus estimated to be in excess of 25 kcal/mol. In order to confirm the indication from NMR spectroscopy that atropisomerism of this type should be... 

The stereochemistry of the nucleophilic reaction of the enolate ion of 1,4-dihydro-4-methoxycarbonyl-l-methylpyridine with and (5 )-(+)-2-bromobutane has... 

Isoxicam Isoxicam, 1,1-dioxide 4-hydroxy-2-methyl-A-(5-methyl-3-isoxazolyl)-2/7-l,2-benzothiazine-3-carboxamide (3.2.80), is synthesized analogous to piroxicam, using ami-dation of 1,1-dioxide 3-methoxycarbonyl-3,4-dihydro-2-//-l,2-benzothiazine-4-one (3.2.78) in the last stage with 3-amino-5-methylisoxazole, instead of 2-aminopyridine [127-130]. 

Diese Reaktionsart ist bei den Addukten aus Butadien-carbonsaure-Derivaten mit der Carboxylgmppe in 3-Stellung allein verwirklicht dabei entstehen 3-Amino-a-pyrone [58, 70, 72). So geht das N-p-Chlorphenyl-3-methoxycarbonyl-6-phenyl-3.6-dihydro-1.2-oxazin bei der Chromato-graphie an Aluminiumoxid in 3-p-Chloranilino-6-phenyl-a-pyron uber (55), der Mechanismus ist analog dem der Pyrrolbildung. 

Dihydro-4,5-dimethyl-3-(hydroperoxy)-2-[4-(methoxycarbonyl)phenyl]isothiazole 1,1-dioxide (AFUPOG) 1.461 1.417 106.6 97... 

Ring contraction with desulfurization occurs when the 4//-l,3-thiazines 131 are reacted with potassium /-butoxide (Scheme 7) <2004TL5913>. The bis(methoxycarbonyl)pyrroles 132 are not isolated but instead give the 4-oxo, 5 dihydro-2//-pyrrolo[3,4-c]quinolines 133 and 134. 

The stereospecific formation of 5,6-dihydro-l,4-dithiins from the reaction of the 13-dithiete 60 with alkenes has been shown to proceed through its valence isomer, l,2-bis(methoxycarbonyl)ethane-13-dithione (Scheme 42) <99JOC8489>. 

N-CH3 2 c6h5 3-Methoxycarbonyl-7-methyl-3-phenyl-5H-6,7-dihydro-imidazolo [7,2-c] imidazol) 60 117... 

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