Stereoselective Synthesis of syn-and anti-3a-Hydroxyl-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b] indole-2-carboxylic Acid

The structure of syn-and anti-N^b-(p-toluenesulfonyl)-3a-hydroxyl-1,2,3,3a,8,8a-hexahydro pyrrolo[2,3,-b]indole-2-carboxylic t-butyl ester was stercoselectively synthesized by oxidative ring formation of N^b-(p-toluenesulfonyl)-L-tryptophan t-butyl ester in methylene chloride containing dimethyldioxirane(DMDO),the p-toluenesulfonly group and t-butyl group can be easily removed by sodium naphthalenide and trifluoroacetic acid,respectively.     

A Selective Synthesis of 2-Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno[2, 3-d]pyrimidin-4（3H）-ones

2-Alkylamino-5, 6, 7, 8-tetrahydrobenzothieno [2,3-d] pyrimidin-4(3H)-ones 7 were synthesized by a new selective synthetic method, which includes aza-Wittig reaction of iminophosphorane 4 with aromatic isocynate to give carbodiimide 5 and subsequent reaction of 5 with various aliphatic primary amine in the presence of EtO^-Na^ .     

Synthesis of Fluoroalkylated Heterocycles via the Reaction of 3-（1-Hydropolyfluoroalkenyl）-l-oxo-2,4,1-benzoxazines with Dinucleophilic Reagents

The reaction of 3-（1-hydropolyfluoroalkenyl）-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was investigated. 7-Fluoroalkyl-2,3-dihydro- 1,4-diazepine[ 1,2-d]quinazolin- 11-ones 2, 2-fluoroalkylisoxazolo[3,2-b]quinazolin-9-ones 3 and 2-fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2-diaminoethane, hydroxylamine hydrochloride and 1,2-diaminobenzene respectively.     

Synthesis of （3aS,6aR）- 1,3-Dibenzyl-tetrahydro- 1H-thieno[3,4-d]-imidazole-2（3H）-one-4-ylidenepentanoic Acid and Characterization of Its Crystal

1 INTRODUCTION The title compound, (3aS,6aR)-1.3-dibenzyl- tetrahydro-1H-thieno[3,4-d]-imidazole-2(3H)-one- 4-ylidenepentanoic acid 3, is a key intermediate for the synthesis of d-biotin 1 (VITH, Fig. 1) which has been widely used not only as a pharmaceu…     

Rearrangement of 2—Benzothiazolylthioacetyl hidrazide in Ethanol Solution of Potassium Hydroxide：Synthesis of s—Triazolo[3,4—b] benzothiazol—3—thiol and Its Derivatives

A novel rearrangement reaction about 2-benzothiazolylthioacetyl hydrazide (1) to produce s-triazolo[3,4-b] benzothiazol-3-thiol (3) in the presence of KOH and CS2 was described.Other way to synthesize 3 from 2-benzothiazolyl-hydrazine (2) under the same condition was compared and the Mannich reaction of compound 3 was reported too.Their structures were established by elemental analyses,IR,^1H nmr and MS spectra.     

Reaction of 2,3-Dihydro-1,5-benzothiazepines and Phenylacetyl Chloride in the Presence of Triethylamine： A New Aspect on the Formation Mechanism of Dihydro-1,3-oxazin-4-one Derivatives

2a,4-Disubstituted 2,2a,3,4-tetrahydro-2-phenyl-1H-azeto[2,1-d][ 1,5]benzothiazepin-1-ones, as well as 2-substi-tuted 2,3-dihydro-3-phenylacetyl-2-styryl-benzothiazoles and 4a,6-disubstituted 3- .benzyl-4a,5-d/hydro-2-phenyl-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, were obtained from the reaction of 2,4-disubstituted 2,3-dihydro-1,5-benzothiazepines with phenylacetyl chloride in the presence of triethylamine. The mechanism for the formation of 4a,5-dihydro-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, 2,3-dihydro-1,3-oxazin-4-one derivatives, was suggested.     

The Rearrangement of 2—Benzothiazolylthioacetyl Hydrazide in Synthesis of s—Triazolo[3,4—b]benzothiazole—3—thiol

The rearrangement reaction of 2-benzothiazolylthioacetyl hydrazide 1 with potassium hydroxide and carbon disulfide in ethanol to produce s-triazolo [3,4-b] benzothiazole-3-thiol 3 was described. 3 also can be obtained from 2-benzothiazolylhydazine 2 and the two methods for getting 3 were compared. Mannich reaction of compounds 3 was reported too.     

Synthesis of thiopyrano[4″,3″:4′,5′]pyrido[3′,2′:4,5]furo[3,2-d]pyrimidines

<正>Reactions of the 6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrile derivative 1 withα-halo-carbonyl compounds gave the ortho-substituted intermediates 2a-c which were converted into furo[2,3-b]thiopyrano[4,3-d]pyridines 3a-c by fusion of a furan moiety under basic conditions.Further cyclization of 3a-c led to a fusion of a pyrimidine ring,yielding the tetracyclic products 6,7 and 8.In addition,condensation of 6 with various aromatic aldehydes afforded the corresponding imines 9a,b.Mannich reaction of 7 gave products 10a,b.     

Preparation and Electrochemical Properties of 3-Pyridinyl-6-aryl-1, 2, 4-triazolo [3, 4-b][1, 3, 4]thiadiazoles

A series of 3-pyridinyl-6-aryl-1, 2, 4-triazolo[3, 4-b][1, 3, 4]thiadiazoles(PATT) were prepared, the structures were confirmed by 1R and ^1H NMR spectra. The results of cyclic voltammetry measurements imply that all these compounds have a higher electron affinity (EA) than 2-(4-biphenyl)-5-(4-tert-butyl phenyl)-1, 3. 4-oxadiazole (PBD) which implies that PATT could be acting as better electron acceptors than widely used electron transporting material PBD.     

Synthesis of Fluoroalkylated Heterocycles via the Reaction of 3-(1-Hydropolyfluoroalkenyl)-1-oxo-2,4,1-benzoxazines with Dinucleophilic Reagents

The reaction of 3-(1-hydropolyfluoroalkenyl)-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was inves-tigated.7-Fluoroalkyl-2,3-dihydro-1,4-diazepine[1,2-d]quinazolin-11-ones 2,2-fluoroalkylisoxazolo[3,2-b]quin-azolin-9-ones 3 and 2-fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2-diaminoethane,hydroxylamine hydrochloride and 1,2-diaminobenzene respectively.     

Synthesis of rac-(1R,4aR,9aR)-2-methyl-1,3,4,9a-tetrahydro-2H-1,4a-propanobenzofuro[2,3-c]pyridin-6-ol. An unusual double rearrangement leading to the ortho- and para-f oxide-bridged phenylmorphan isomers

In an attempt to obtain the para-f isomer, rac-(1R,4aR,9aR)-2-methyl-1,3,4,9a-tetrahydro-2H-1,4a-propanobenzofuro[2,3-c]pyridin-6-ol, via mesylation of an intermediate 9[small alpha]-hydroxyphenylmorphan, we obtained, instead, a rearranged chloro compound with a 5-membered nitrogen ring, 7-chloro-3a-(2,5-dimethoxyphenyl)-1-methyl-octahydroindole. This indole underwent a second rearrangement to give us the desired para-f isomer. The structures of the intermediate indole and the final product were unequivocally established by X-ray crystallography. A resynthesis of the known rac-(1R,4aR,9aR)-2-methyl-1,3,4,9a-tetrahydro-2H-1,4a-propanobenzofuro[2,3-c]pyridin-8-ol, the ortho-f isomer, was achieved using the reaction conditions for the para-f isomer, as well as under Mitsunobu reaction conditions where, unusually, the oxide-bridge ring in the 5-phenylmorphan was closed to obtain the desired product. The synthesis of the para-f isomer adds an additional compound to those oxide-bridged phenylmorphans that were initially visualized and synthesized; the establishment of the structure and configuration of 8 of the theoretically possible 12 racemates has now been achieved. The X-ray crystallographic structure analysis of the para-f isomer provides essential data that will be needed to establish the configuration of a ligand necessary to interact with an opioid receptor.     

Acetylenchemie, 33. Mitt.: Synthese von 2-substituierten Dihydrofuro[2,3-b]chinolinen

Summary The reaction of 3-iodo-4-methoxy-2(1H)-quinolinone (1) and 3-iodo-4,6,8-trimethoxy-2(1H)-quinolinone (2) with 2-methyl-3-butyn-2-ol under modified Heck-conditions gave the 2-substituted derivatives 2-(1-hydroxy-1-methylethyl)-4-methoxyfuro[2,3-b]-quinoline (3) and 2-(1-hydroxy-1-methylethyl-4,6,8-trimethoxyfuro[2,3-b]-quinoline (4). By a subsequent hydrogenation-reaction with a homogeneous catalyst (PtO₂/Rh₂O₃), the furoquinoline-derivatives yielded the dihydrofuro-[2,3-b]quinolines, identified as 2-(1-hydroxy-1-methylethyl-4-methoxy-2,3-dihydrofuro[2,3-b]quinoline (5) (racemic platydesmine) and 2-(1-hydroxy-1-methylethyl)-4,6,8-trimethoxy-2,3-dihydrofuro-[2,3-b]quinoline (6) (racemic precursor of O⁴-methylptelefolonium salt).

     

An efficient synthesis of novel benzo[b]pyrido[3',2':4,5] thieno[2,3-e][1,6]naphthy-ridine-8-ones

An efficient method for the synthesis of novel benzo[b]pyrido[3',2':4,5] thieno[2,3-e][1,6] naphthyridine-8-one derivatives has been developed using a Pictet-Spengler reaction between 4-(3-aminothieno[2,3-b]pyridin-2-yl)quinoline-2-ones, which could be obtained from the alkylation of 4-bromomethylquinoline-2-ones with 3-cyanopyridine-2-thione followed by a Thorpe-Ziegler isomerization, and aromatic aldehydes under p-TsOH as catalysis in good yields.     

Bidirectional synthesis of the central amino acid of chloptosin

[reaction: see text] An efficient total synthesis of (2S,2'S,3aR,3'aR,8aR,8'aR)-6,6'-dichloro-3a,3'a-dihydroxy-1,1',2,2',3,3a,3',3'a,8,8a,8',8'a-dodecahydro-5,5'-bipyrrolo[2,3-b]indole-2,2'-dicarboxylic acid, the central amino acid component of chloptosin (1), is described. Starting from m-chloronitrobenzene, this C(2)-symmetrical amino acid was synthesized by using a 14-step route, in which a Zinin benzidine rearrangement, intramolecular Heck reaction, and selenocyclization and oxidative deselenation served as key steps. The absolute stereochemistry of the target was confirmed by X-ray single-crystal studies on a key intermediate (17).     

Investigation of nitrogen- and sulfur-containing heterocycles. 38. Reactions of 2-mercapto-3-ureidopyridines with halo β-diketones

The reaction of 2-mercapto-3-ureido-6-chloropyridine with chlorodibenzoylmethane in the presence of alkali leads to 2-(benzoylmethylthio)-3-benzamido-6-chloropyridine, whereas the reaction in the absence of alkali leads to 2-chloro-6-phenyl-7-benzoylpyrido[2,3-b] [1,4]thiazine. Under similar conditions 2-(diacetylmethylthio)-3-ureido-6-chloropyridine, 2-(acetylmethylthio)-3-ureido-6-chloropyridine, and 2-chloro-6-methyl-7-acetylpyrido[2,3-b][1,4]thiazine were obtained from 2-mercapto-3-ureido-6-chloropyridine and chloroacetylacetone. Treatment of 2-(diacetylmethylthio)-3-ureido-6-chloropyridine with alcoholic alkali leads to 2-(acetylmethylthio)-3-ureido-6-chloropyridine. 2-Chloro-6-phenyl-7-acetylpyrido-[2,3-b] [1,4]thiazine and 2-(benzoylmethylthio)-3-ureido-6-chloropyridine are formed in the reaction of 2-mercapto-3-ureido-6-chloropyridine with chlorobenzoylacetone in the presence of an equimolar amount of alkali, while 2-(benzoylmethylthio)-3-acetamido-6-chloropyridine is formed when excess alkali is used. See [1] for communication 37. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 787–790, June, 1980.     

Endo-selective quenching of hexahydropyrrolo[2,3-b]indole-based N-acyliminium ions

Radical decarboxylation of L-tryptophan-derived (2S,3aR,8aS)-8-arylsulfonyl-1,2-di(methoxycarbonyl)-1,2,3,3a,8,8a-hexahydro-2H-pyrrolo[2,3-b]indoles 8 and 9 in the presence of diphenyl diselenide results in the endo-selective formation of (2R,3aR,8aS)-8-arylsulfonyl-1-methoxycarbonyl-2-phenylselenyl-1,2,3,3a,8,8a-hexahydro-2H-pyrrolo[2,3-b]indoles 10 and 11. These selenides, in conjunction with Lewis acids, serves as precursors to the corresponding N-acyl iminium ions, which undergo selective endo-face quenching by allyltributylstannane, allyltrimethylsilane, propargyltrimethylsilane, and trimethylsilylcyanide. Stereochemical assignments rest on NMR data and crystallographic studies. The endo-selective nature of these reactions is interpreted in terms of minimization of allylic strain at the transition state for nucleophilic attack on the N-acyl iminum ion.     

Synthesis of naphtho[2',3':4,5]imidazo[2,1-<Emphasis Type="Italic">b</Emphasis>][1,3]-thiazole-5,10-dione and naphtho[2',3':4,5]imidazo-[2,1-<Emphasis Type="Italic">b</Emphasis>][1,3]benzothiazole-7,12-dione

The reaction of 2,3-dibromo-1,4-naphthoquinone with 2-aminothiazole in MeONa/MeOH at 60oC for 3 h gave naphtho[2',3':4,5]imidazo[2,1-b][1,3]thiazole-5,10-dione in 64% yield. The reaction of 2,3-dibromo-1,4-naphthoquinone with 2-aminobenzothiazole under the above-mentioned conditions gave 2-(benzo[d]thiazol-2-ylamino)-3-bromonaphthalene-1,4-dione in 64% yield, which on treatment with Na/THF or NaN₃/acetone under reflux conditions gave naphtho[2',3':4,5]imidazo[2,1-b][1,3]- benzothiazole-7,12-dione in 69 and 56% yields, respectively.     

Synthesis and properties of 2-ethoxycarbonyl-3-amino-2,3-dehydroquinuclidine

The reduction of 2-ethoxycarbonyl-3-oxoquinuclidine oxime hydrochloride leads to 2-ethoxycarbonyl-3-amino-2,3-dehydroquinuclidine, from which pyrimido[5,4-b]quinuclidine derivatives were obtained by reaction with formamide, methyl isocyanate, and phenyl isothiocyanate. It is shown that 7-hydroxypyrazolo[4,3-b]quinuclidine is formed in the reaction of 2-ethoxycarbonyl-3-acetamido-2,3-dehydroquinuclidine with hydrazine hydrate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 971–974, July, 1983.     

[3,3]-sigmatropic rearrangement of allyl 2-benzothienyl sulfide

Allyl 2-benzothienyl sulfide at 20–120 °C undergoes a [3,3]-sigmatropic rearrangement to give 3-allylbenzothiophene-2-thiol. The kinetic parameters of the reaction were studied. Under the experimental conditions the thiol undergoes cyclization to give 2-methyl-2,3-dihydrobenzothieno[2,3-b]thiophene, 2-methyl-benzothieno[2,3-b]thiophene, and benzothieno[2,3-b]dihydrothiopyran. Allyl 3-methyl-2-benzothienyl sulfide does not form a thiol even at 150–190 °C but rather forms only bis(3-methyl-2-benzothienyl) disulfide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 615–618, May, 1981.