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1.
6,7-Dimethoxy-2-phenyl-4-1,3-benzothiazine (1) and 6,7-dimethoxy-4-phenyl-2-1,3-benzothiazine (2) react with substituted acetyl chlorides to give linearly, and new angularly condensed β-lactam derivatives (4,5). Heating of the latter compounds with hydrogen chloride in anhydrous ethanol leads to the formation of the corresponding 4- and 2-1,3-benzothiazinium chloride, respectively. The configurations of these compounds (the mutual positions of the substituents relative to the β-lactam ring) were determined by 1H and 13C studies, also making use of the aromatic solvent-induced shifts. 相似文献
2.
6, 7-Dimethoxy-2-l,3-benzothiazine derivatives (, ) react with substituted acetyl chlorides to give angularly condensed β -lactams (-, , ). The compound was epimerised to the derivative . From the interaction of 2-phenyl-6,7-dimethoxy-4-1,3-benzothiazine () and α -chloro-phenylacetyl chloride two stereoisomeric β -lactam derivatives (, ) were isolated, whereas in the other cases studied the reactions leading to β -lactams proved to be stereospecific. Analogous reactions of -methyl-6,7-dimethoxy-2-l,3-benzothiazine () furnished the enamides ,, . Structures of the new compounds and configurations of the diastereomers were elucidated by IR and NMR spectroscopy. 相似文献
3.
Lajos Fodor János Szabó Erzsébet Szúcs Gábor Bernáth Pál Sohár József Tamás 《Tetrahedron》1984,40(20):4089-4095
6,7-Dialkoxy-2-aryl-41-1,3-benzothiazines (1a?) react with chloroacetyl chlorlde to give condensed β-lactam derivatives (2a?). Basic treatment of 2a? in methanol led to the corresponding 1,4-banzothiazepine derivativee (3a?) ring expansion. The structures of the products were determined by IR, NMR and MS studies 相似文献
4.
Lajos Fodor Jnos Szab Gbor Bernth Pl Sohr David B. Maclean Richard W. Smith Ichiya Ninomiya Takeaki Naito 《Journal of heterocyclic chemistry》1989,26(2):333-337
6H,8H-Isoquino-1,3-benzothiazin-8-ones have been prepared by reaction of 6,7-dimethoxy-2H-1,3-benzo-thiazines with homophthalic anhydride and by photocyclization of 3-benzoyl-4-methylene-6,7-dimethoxy 2H-1,3-benzothiazine. The compounds are thia analogues of protoberberine alkaloids containing a sulfur atom at C-5 and a lactam function at C-8. The mass spectra of the title compounds are discussed. 相似文献
5.
2,4,6-Triphenylpyrylium with thiosemicarbazide and thiocarbohydrazide, gives 2-pyrazolines and which undergo cyclization yielding pyrazolo(1,5-c]pyrimidine 5 and pyrazolo [2,3-d]-1,2,4-triazepine derivatives, respectively. Reaction of with phenacyl bromides gave 1,3-thiazolo[3,2-b]pyrazolo [2,3-d]-1,2,4-triazepin-4-iums . Compound on treatment with phenacyl bromides gave 1-(4'-aryl-thiazol-2'-yl)-2-pyrazoline derivatives . Compound reacts with acyl chlorides to give pyrazolo[1,5-c]pyrimidine derivatives , and with aromatic aldehydes giving the 2-(Δ2'1 pyrazolin-1-yl)-5-aryl-1,3,4-Δ2-thiadiazolines which were easily converted to the corresponding 2-(Δ2-pyrazolin-1-yl)-5-aryl-1,3,4-thiadiazoles . 相似文献
6.
Thermal nitrogen extrusion of 2-methylene-6,7-diazabicyclo[3.2.2]non-6-enes and 6,7- diazabicyclo[3.2.2]nona-2,6-diene,6 proceeded easily to give closure and cleavage products the corresponding 5-methylene-1,4-cycloheptylenes and 4-cyclohepten-1,3-ylenes, respectively. 相似文献
7.
Acid-catalysed ring opening of the spirodienones () and () using p-toluene-sulphonic acid affords the styrène derivatives () and (), while treatment with acetic anhydride/H2SO4 affords the furan derivatives () and (). 相似文献
8.
- The corresponding - and -methyl- and -benzyl-5,6- and 4,5-tetramethylenetetrahydro-l,3-oxazines were synthesized from - and -methyl and-benzyl-2- aminomethyl-1-cyclohexanols , from - and -methyl- and benzyl -2-hydroxymethyl-1-cyclohexylamines by reaction with formaldehyde. The aminoalcohols and were prepared in considerably higher yields than in earlier procedures. NMR spectroscopy showed that the isomers of the synthesized oxazines were conformationally homogeneous in solution, and their preferred conformation (inside or outside) depended on the steric requirement of the groups attached to the anellation points, whereas a bulky C-2 substituent had no influence on the predominant conformation. The structure of -benzyl--4,5-tetramethylenetetrahydro-1,3-oxaziniumpicrate . determined by X-ray diffraction analysis, was in agreement with the predominant N-outside conformation of the corresponding base, established by means of NMR spectroscopy. 相似文献
9.
Abstract
6,7-Dimethoxy-2H-1,4-benzothiazin-3(4H)-one reacts with dimethylformamide dimethylacetal (DMF-DMA) to give the novel enaminone 2-(dimethylaminomethylene)-6,7-dimethoxy-2H-1,4-benzothiazin-3(4H)-one. The reaction of the latter with various active methylene compounds afforded pyrido[3,2-b][1,4]benzothiazines. Also, coupling of the enaminone with diazotized aniline derivatives gave 2-(arylhydrazono)-6,7-dimethoxy-2H-1,4-benzothiazin-3(4H)-ones. Spectral data indicated that the latter compounds exist predominantly in the hydrazone tautomeric form. In addition, coupling of the enaminone with diazotized heterocyclic amines afforded tetra- and pentaheterocyclic ring systems. The antitumor and antimicrobial activity of some of the synthesized compounds was screened. 相似文献10.
Yoshikatsu Ito Meng Ji-Ben Shin Suzuki Yoshitaka Kusunaga Teruo Matsuura Keiichi Fukuyama 《Tetrahedron letters》1985,26(17):2093-2096
In contrast to simple imidazoles, 1-methy1–2,4,5-triphenylimidazole () produced stable oxetane photoadducts - with good efficiency upon irradiation in the presence of benzophenone derivatives - in acetonitrile solution. Irradiation in the solid-phase was also studied. The oxetanes - readily underwent cycloreversion by acid catalysis or by heating. 相似文献
11.
On acetone-sensitization, 5-bromo-1,3-dimethyluracil ( reacts with Nb-methoxycarbonyltryptamine ( under the assistance of an electron carrier such as 2-methoxynaphthalene to give a coupling product . A mechanism involving a double electron transfer via the triplet state of is proposed. 相似文献
12.
Colin G. Pitt Herbert H. Seltzman Yousry Sayed Charles E. Twine David L. Williams 《Tetrahedron letters》1978,19(1):37-40
The synthesis of (6aR, 10aR)-trans-3-[1′,3′-dithian-2′-yl]-6a,7,8,10a-tetrahydro-6,6,9- trimethyl-6H-dibenzo[b,d]pyran-l-ol t-butyldimethylsilyl ether () is reported. The use of this compound as a source of side chain derivatives of cannabinoids is illustrated by syntheses of 1′-,2′-,3′- and 4′-hydroxy-Δ9-THC, and 3-carboxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran-1-o1 (). 相似文献
13.
The hetero-Diels-Alder reaction between 1,3-dimethoxy-1-trimethylsilyloxybutadiene , and cinnamaldehyde, produces (±) kawain in 75% and 84% yield respectively when catalyzed by Eu(fod)3 or Yb(fod)3. When Ag(fod) is employed as the catalyst a unique condensation reaction occurs which produces two acyclic diastereomers in 72% yield. 相似文献
14.
3-Methylisoguanosine () has been synthesized from 5-(cyanomethylamino)-1(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)imidazole-4-carboxamide () through the carbonitrile (). 相似文献
15.
16.
A short and convenient synthesis of phosphatidyl-α-diglucosyldiglyceride (i.e. compound ) and two related Streptococci glycolipids (i.e. compounds and ) will be presented. 4',6'-Tetraisopropyl-disiloxane-1,3-diyl (TIPS) protected α-glucosyl diglyceride (i.e. compound ) turned out to be a suitable protected precursor. Thus, compound was selectively condensed with glucosyl bromide to afford . Removal of the protecting groups from gave glycolipid . The “dynamic” properties of the TIPS pro- tecting group were utilized to convert 4',6'-TIPS protected into 3',4'- TIPS protected derivative . Compound could then be condensed with either a stearoyl fatty acid or a phosphatidyl moiety to give the fully protected derivatives and , respectively. Finally, removal of all the protecting groups from and afforded the glycolipid and glycophospholipid , respectively. 相似文献
17.
The photochemical reactions of tetracyclic azo compounds () giving and via diazoethane derivatives () were investigated in addition to the nitrogen extrusion reactions leading to tetracyclo[4.3.0.02,9.05,7nonenes (). 相似文献
18.
Treatment of -alkylacetylenes, generated from 1--1- alkenephosphonates, with silyl enol ethers in the presence of a catalytic amount of tetrabutylammonium fluoride gives good yields of -alkyl-substituted propargyl alcohols or 4-(1--alkylidene)-1,3-dioxolane derivatives, the latter being converted to tie corresponding α-hydroxy ketones. 相似文献
19.
The reaction between 1,3-cyclohexanediones and chalcones (or their vinilogs) in the presence of 2.5 equiv of cerium(IV) ammonium nitrate afforded trans-2-arylcarbonyl-3-aryl (or styryl)-2,3,6,7-tetrahydrobenzofuran-4(5H)-ones in good to excellent yields and in high diastereoselectivities. The method was also extended to the preparation of derivatives of the 5,6-dihydro-2H-cyclopenta[b]furan-4(3H)-one system. The fused 2,3-dihydrofuran derivatives were transformed into 1-alkyl-2-acyl-3-aryl-6,7-dihydroindole-4(5H)-ones by 2,3-dehydrogenation followed by reaction with primary amines. The direct reaction of the tetrahydrobenzofuran-4(5H)-one compounds derived from dimedone with amines gave 1-alkyl-2-alkylimino-3-aryl-6,7-dihydroindole-4(5H)-ones, while starting materials derived from 1,3-cyclohexanedione underwent an unprecedented 2-deacylation reaction and gave 1-alkyl-3-aryl-6,7-dihydroindole-4(5H)-ones. 相似文献
20.
V. A. Osyanin E. A. Ivleva D. V. Osipov Yu. N. Klimochkin 《Chemistry of Heterocyclic Compounds》2011,47(7):845-850
Products of heterocyclization, 9,10-dimethoxy-12,13-dihydro-7aH,15H-naphtho[1',2':5,6][1,3]oxazino-[2,3-a]isoquinolines, were
isolated on condensing 6,7-dimethoxy-3,4-dihydroisoquinoline with 1-dimethylaminomethyl-2-naphthols. In the case of o-hydroxybenzyl alcohols products of a Michael aza reaction, 2-[(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)methyl]phenols
were obtained. 相似文献