5-Methoxycarbonyl-7-methyl-2,3-dihydro

Methoxycarbonyl methyl-1 //-pyrrolo 3,4-r pyridine-l,3(2//)-dione (47) has been reported to undergo ring expansion to afford methyl 4-hydroxy-1-oxo-l,2-dihydro-2,7-naphthyridine-3-carboxylate (48) (MeONa/MeOH, 100°C ... 

Methoxycarbonyl-methyl)- -methyl-5,6-dihydro-(dibenzo[b d] phosphorin)-5- osid 295 Zu 0,21 g (2,5 mmol) Propiolsaure-methylester in 5 ml THF und 0,2 ml Wasser gibt man innerhalb 10 Min. Lropfenweise die Losung von 0,5 g (2,7 mmol) 5-Methyl-dibenzOphosphol in 10m/ THF. AnschlieBend erhitzt man 12 Stdn. zum RiickfluB, dampft ein und kristallisiert den Riickstand aus Ether und Benzol Ausbeute 0,5 g (70°/o) Schmp. 145-148°. 

Methoxycarbonyl-methyl)-5-phenyl-5,6-dihydro- dibenzo b,d]phosphoririy-5-oxid (R = C6H5) 33% 5-Benzyl-6-(methoxycarbonyl-methyl)-5,6-dihydro-(dibenzo[b,d]phosphorin -5-oxid (R — CH2-C6H5) 16% ... 

Oxazol 4-Methoxycarbonyl-3-(methoxycarbonyl-methyl)-2-methyl-2,3-dihydro- E6a, 682... 

Furan 3,4-Bis-[methoxycarbonyl-methyl]-2,5-dihydroxy-2,5-dihydro- E14a/1, 451 (Furan-Oxid.) a-o-Gluco-furanose 5,6-O-Carbonyl-1,2-O-isopropyliden- E4, 88/90 (H - CHO)... 

Bis(methoxycarbonylmethyl)amme (255) gave l,4-bis(methoxycarbonyl-methyl)-3,6-dihydro-2,5(lH, 4//)-pyrazinedione (256) (EtsB or Ph llSi, PhMe, reflux, 48 h 54%) also analogues ... 

This unusual transformation is exemplified in the isomerization of l-(o-methoxy-carbonylbenzoyl)-l,4-dihydro-3(2f/)-cinnolinone (189) into 2-[o-(methoxycarbonyl-methyl)phenyl]-l,4(2//,3//)-phthalazinedione (190) by refluxing in methanolic sulfuric acid or aqueous methanolic potassium hydrogen carbonate for 90 min or 7 h, respectively yields were unstated. ... 

The condensation of aldehydes with thiocyanoacetic esters, catalysed by potassium fluoride or potassium carbonate, gave as minor products yV-carbamoyl-2-imino-5-alkyl(or aryl)-l, 3-oxathiolan-4-carboxylic esters, in which the 4,5-c/j-isomers predominated according to n.m.r. spectroscopy. l,3-Oxathiolan-2-thione was converted into dimethyl 1,3-dithiol-2-one-4,5-dicarboxylate and ethylene on treatment with dimethyl acetylene-dicarboxylate, and the transformation of methyl 2-methoxycarbonyl-methyl-1,3-oxathiolan-2-carboxylate into dimethyl-5,6-dihydro-l, 4-oxa-thiin-2,3-dicarboxylate by chlorination at low temperatures found analogy in the reactions of 2,2-dialkyl-l,3-oxathiolans. Thiomethoxymethyl hexachloroantimonate reacted with potassium t-butoxide to give mainly 3,5,5-trimethyl-l,3-oxathiolanium hexachloroantimonate the mechanism of this remarkable reaction was not settled. ... 

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). 

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... 

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... 

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... 

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]. 

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

An approach to the synthesis of angularly substituted polycyclics through the Diels-Alder cycloaddition of dihydrothiophenes has been devised (69JA7780). The easily prepared 2,5-dihydro-4-methoxycarbonyl-2-thiopheneacetic acid methyl ester (316) was heated at 180 °C with excess butadiene to yield (317). Desulfurization and double bond reduction of the cycloadduct with W-5 Raney nickel gave (318) which was characterized by conversion to the corresponding diacid and comparison with an authentic sample. Dieckmann cyclization of (318) is known to lead to the 5-methyl-1-hydrindanone (319 Scheme 68). The use of other dienes in the [4 + 2] cycloaddition process will, of course, produce more highly functionalized hydrindanones. 

Chemical Name 2-[(2-Aminoethoxy)methyl]-4-(2-chlorophenyl)-3-ethoxycarbonyl-5-methoxycarbonyl-6-methyl-l,4-dihydro pyridine monobenzenesulfonate... 

B) Preparation of 7-Chloro-3-Methoxycarbonyl-5-Phenyl-2-Oxo-2,3-Dihydro-lH-Benzo[f]-l,4-Diazepine (4347 CB) A solution of 9.2 g (0.04 mol) of compound 4356 CB in 20 ml of methanol is added dropwise, in the course of one hour and 30 minutes, to a boiling solution of 9.2 g (0.05 mol) of the hydrochloride of methyl aminomalonate in 30 ml of methanol. When this is completed, heating under reflux is continued for 30 minutes and the product then concentrated to dryness under reduced pressure. The residue is taken up in water and ether, the ethereal layer separated, the product washed with water and dried over sodium sulfate. The solvent is evaporated under reduced pressure. The residue, which consists of the methyl ester, could not be obtained in the crystalline state. It is dissolved in 25 ml of acetic acid, heated under reflux for 15 minutes, the product evaporated to dryness and the residual oil taken up in ether. A colorless solid separates which is filtered by suction and recrystallized from methanol. Colorless crystals are obtained (4.7 9) MPk (Kofler block) 226°C. A second crop (1.5 g) is obtained on concentration of the mother liquor MPk (Kofler block) 222°C total quantity 6.2 g, corresponding to a yield of 47%. 

Carboxy-6-hydroxythiazolo[2,3-/ [ 1,6]-naphthyridin-4-ium-3-carboxylate (152) (beminamycinic acid) underwent exhaustive methylation to afford methyl 8-methoxy-6-(l-methoxycarbonyl-2-methylthiovinyl)-5-oxo-5,6-dihydro-1,6-naphthyridine-2-carboxylate (153) (Mel, Ag20 low yield)293 or hydrogenolysis to furnish a separable mixture of 6-(l-carboxylatoethyl)-8-hydroxy-l,2,3,4-tetrahydro-l,6-naphthyridin-6-ium-2-carboxylic acid (154) and 8-hydroxy-1,2,3,4-tetrahydro-l,6-naphthyridine-2-carboxylic acid (155) (Raney Ni, NaOH, H20 unstated yields).274... 

Ethan- -S,S-dibutylester E2, 408 Ethan- -S.S-diethylester E2, 408 Ethan- -S-[ l-(2,2-dimethyl-hydra7inocarbonyl)-ethylesterj-O-ethylester E2, 452 Ethan- -S-(ethoxycarbonyl-isopropyloxy-methyl-estem)-0-ethy[ester E2, 452 Ethan- -0-[(ethoxy-methylthio-methylen)-amin-ester)-S-propargylester E2, 457 Ethan- -O-ethylester E2, 452, 453, 455 Ethan- -O-ethylester-S-(2-ethylthio-ethylester) XII/1, 591 E2, 420, 449 Ethan- -S-ethvlester-0-(2-methoxycarbonyl-l-methyl-vinyiester) E2, 456 Ethan- -0-ethylester-S-(4-methyl-3-methylthio-5-oxo-4,5-dihydro-1,2,4-triazolomethylester)... 

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