Preparation of single-enantiomer semiochemicals using 2-methoxy-2-(1-naphthyl)propionic acid and 2-methoxy-2-(9-phenanthryl)propionic acid

Enantioresolution of 3-octanol, 6-methyl-5-hepten-2-ol (sulcatol), and 1-octen-3-ol was conducted using (S)-(+)-2-methoxy-2-(1-naphthyl)propionic acid (MαNP acid) and (S)-(+)-2-methoxy-2-(9-phenanthryl)propionic acid (M9PP acid). In each case, the diastereomeric esters obtained were readily separated by HPLC. The stereochemistry of the esters could be assigned from their respective ¹H NMR analyses. Solvolyses of the esters gave enantiopure alcohols and acids. MαNP and M9PP acids displayed almost equivalent properties in ¹H NMR anisotropy. The chiral resolving ability of M9PP acid was slightly superior to that of MαNP acid in HPLC.     

α-(2-噻唑基脲基)膦酸二苯酯的合成

报道了一种简便的合成取代脲基膦酸酯的通用的新方法。在二氯甲烷中,三乙胺为缚酸剂的条件下,α-氨基膦酸二苯酯与三聚光气反应形成α-异氰酸基膦酸酯2,2不经分离,直接与2-氨基(苯并)噻唑加成得到α-(2-噻唑基脲基)膦酸二苯酯3,产率55.0%-88.9%。     

Synthesis of Insecticidally Active 3-Phenoxy Benzyl and α (RS) Cyano-3-Phenoxy Benzyl (±) Trans 2-(2, 2-Dichlorovinyl) Spiro (2,5)-Octane-1-Carboxylates

Cyclopropane carboxylic acid esters, possessing spirofused cycloallcyl rings, in place of the conven- tional gem-dimethyl group of natural pyrethrins and synthetic pyrethroids also exhibit good insecticidal I activity against a wide range of insect species. In addition, these compounds exhibit knock-down activity on flying insects. Someoc-cyan0-3-phenoxy benzyl esters of (±) - cis and (±) trans 2-(2,2-dichlorovinyl)-spiro (2,5)-octane-l-carboxylic acid and the lower spiro cycloalkyl members of the homologous series, have been synthesised and found to be active against, musca domestica, cotton leafworm etc, with good knock-down effect. The acid moieties of the above esters have been synthesised by reaction of alkyl diazo acetates on suitably substituted olefins 2, 3.     

Acylation of Alcohols and Amines with Vinyl Acetates Catalyzed by Cp(2)Sm(thf)(2)

Cp(2)Sm(thf)(2) was found to be an efficient catalyst for the acylation of alcohols and amines with esters under mild conditions. In the present acylation, vinyl and isopropenyl acetates served as good acylating agents. Thus, a variety of alcohols and amines underwent acylation with vinyl and isopropenyl acetates in the presence of Cp(2)Sm(thf)(2) to give the corresponding esters and amides in good to excellent yields. This catalytic acylation of alcohols and amines offers an additional useful method by the use of various esters, instead of acid anhydrides and acid chlorides, as acylating agents under very mild conditions.     

（R）—N—乙酰四氢噻唑—2—硫酮—4—羧酸与醇的反应

（Ｒ）－Ｎ－乙酰四氢噻唑－２－硫酮－４－羧酸与醇反应，在ＳＯＣｌ２存在下得到乙酸酯及四氢噻唑－２－硫酮－４－羧酸酯；在碳酸钾存在下得到乙酸酯及四氢噻唑－２－硫酮－４－羧酸；在二环己基碳二亚胺（ＤＣＣ）存在下得到缩水产物Ｎ－乙酰四氢噻唑－２－硫酮－４－羧酸酯。     

Determination of the absolute configuration of chiral alpha-aryloxypropanoic acids using vibrational circular dichroism studies: 2-(2-chlorophenoxy) propanoic acid and 2-(3-chlorophenoxy) propanoic acid

The enantiomers of 2-(2-chlorophenoxy) propanoic acid and 2-(3-chlorophenoxy) propanoic acid were resolved on a chiral HPLC column and investigated using mid-infrared vibrational circular dichroism (VCD). Experimental infrared vibrational absorption and VCD spectra were measured in CDCl3 solution in the 2000-900 cm-1 region and compared with the ab initio predictions of absorption and VCD spectra. The predicted spectra were obtained with density functional theory using B3LYP/6-31G* basis set for the stable and dominant conformers. But the predicted spectra did not provide unambiguous structural information due to intermolecular hydrogen bonding in solution. To eliminate the hydrogen bonding effects, the acids were converted to the corresponding methyl esters and the experimental absorbance and VCD spectra of methyl esters were measured. B3LYP predicted spectra were also obtained for the stable and dominant conformers of the esters. From a comparison of the experimental VCD spectra of methyl esters with corresponding ab initio predictions, the absolute configurations of esters, and therefore of their parent acids, are unambiguously determined to be (+)-(R).     

The Preparation of Substituted 1(2H)-Isoquinolinones from Dilithiated 2-Methyl-N-arylbenzamides, 2-Methyl-N-(arylmethyl)-benzamides,or 2-Methylbenzoic Acid, 2,2-Dimethylhydrazide

2-Methyl-N-arylbenzamides (N-aryl-ortho-toluamides), 2-methyl-N-(arylmethyl)-benzamides (substituted benzyl, N-benzyl-ortho-toluamides), or 2-methylbenzoic acid, 2,2-dimethylhydrazide (ortho-toluic acid, N,N-dimethylhydrazide), were dilithiated with excess lithium diisopropylamide, and the resulting polyanion-type intermediates were condensed with aromatic esters followed by acid cyclization to the 3-substituted-1(2H)-isoquinolinones (isocarbostyrils).     

2-(5-Bromo-2-furyl)quinoxaline and 3-(5-bromo-2-furyl)-2-quinoxalone

2-(5-Bromo-2-furyl)quinoxaline and 3-(5-bromo-2-furyl)-2-quinoxalone were obtained by the action of bromine on the corresponding quinoxaline derivatives and also by condensation of o-phenylenediamine with, respectively, (5-bromo-2-furyl)glyoxal or (5-bromo-2-furyl)glyoxylic acid esters.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 404–406, March, 1973.     

Heck-mediated synthesis and photochemically induced cyclization of [2-(2-styrylphenyl)ethyl]carbamic acid ethyl esters and 2-styryl-benzoic acid methyl esters: total synthesis of naphtho[2,1f]isoquinolines (2-azachrysenes)

We describe two new closely related total syntheses of naphtho[2,1-f]isoquinolines. The first synthesis consists of a Heck coupling reaction between trifluoromethanesulfonic acid 2-(2-ethoxycarbonylaminoethyl)phenyl esters and styrenes to give [2-(2-styrylphenyl)ethyl]carbamic acid ethyl esters. These compounds cyclize to give (2-phenanthren-1-yl-ethyl)carbamic acid ethyl esters, from which 2-azachrysenes can be obtained in a three-step sequence. The second synthesis includes a new total synthesis of 2-styrylbenzoic acid methyl esters by Heck coupling of methyl o-iodobenzoates to styrenes, followed by the transformation of the resulting benzoic acid derivatives into phenanthrene-1-carboxylic acid methyl esters and then into the target compounds by a six-step sequence including a Bischler-Napieralski cyclization.     

Synthesis and glutamate-agonistic activity of (S)-2-amino-3-(2,5-dihydro-5-oxo-3-isoxazolyl)-propanoic acid derivatives.

(S)-2-Amino-3-(2,5-dihydro-5-oxo-3-isoxazolyl)propanoic acid, (3a) and its analogs (3b--h) were prepared and evaluated for glutamate receptor-agonistic and antifungal activities. Several (S)- and (R)-2-amino-3-isoxazolylpropanoic acid derivatives (3a--d) were synthesized starting with (S)- and (R)-N-tert-butoxycarbonyaspartic acid alpha-methyl esters (4, n = 1) by means of Masamune's chain extension reaction followed by isoxazolone formation with hydroxylamine and subsequent deprotection reactions. Furthermore, (S)- and (R)-N-tert-butoxycarbonylglutamic acid alpha-methyl esters (4, n = 2) were converted to (S)- and (R)-2-amino-4-isoxazolylbutyric acid derivatives (3e-h) via the same sequence of reactions.     

Some transformations in a number of (2-pyridyl)phosphonates

The reaction of sodium diethylphosphite with N-methoxypyridinium methosulfate in a solvent at low temperature makes it possible to obtain diethyl (2-pyridyl)phosphonate in yields up to 75%. The latter was converted to (2-pyridyl)-phosphonic acid dichloride, from which amides, esters, amidochlorides, and (pyridyl)thiophosphonic acid derivatives were obtained.     

新型Rh_2(esp)_2配体手性类似物的合成

以(R)-叔丁基亚磺酰胺为手性助剂,与1,3-苯二甲醛经缩合反应制得关键中间体——(Rs,Rs)-双叔丁基亚磺酰亚胺(7);锂化的羧酸酯与7经不对称加成反应合成了两个新型的Rh_2(esp)_2配体类似物——(Rs,Rs',R,R')-β-胺基羧酸酯和(Rs,Rs',R,R',R,R')-α,β-氮杂环丙烷羧酸酯,产率分别为96%和65%,非对映选择性均大于20∶1。化合物的结构经1H NMR和13C NMR表征。     

R(-)四氢噻唑-2-硫酮-4-羧酸对D,L-氨基酸酯拆分的研究

以新手性拆分试剂R(-)四氢噻唑-2-硫酮-4-羧酸[简称R(-)TTCA]对D,L-氨基酸酯进行手性拆分,分别得到(R)TTCA氨基酸酯盐1a_1f([α]_D²⁰＝-30.40°～-42.70°)及光学活性氨基酸酯2a-2f,其光学纯度为35.4%～75.8%.由1a_1f在碱存在下分解出2a-2f的对映体3a-3f,光学纯度为39.50%～69.10%.用半经验的量子化学PM3方法研究了氨基的碱性、中间产物铵盐生成热和稳定性.     

Syntheses of substituted 2-(l-methyl-2-imidazolyl)quinolines

Reaction of methyllithium with 1-methy1-2-imidazolecarboxaldehyde afforded the corresponding alcohol 2. Oxidation of compound 2 with manganese dioxide gave 2-acety1-1-methylimidazole ( 3 ). Using compound 3 and substituted isatins 4 , the corresponding quinoline-4-carboxylic acids ( 5 ) were prepared. The reaction of acid imidazolides of 5 with appropriate amines yielded the amides 6 . Carbamic acid esters 10 were prepared by the Curtius rearrangement in good yield. Substituted quinolin-4-amines 13 were obtained by the acid hydrolysis of compound 10 (R₁ = t-Bu). Alkylation of amines 13 with diakylaminoalkyl chlorides gave compounds 14 .     

Preparation of single-enantiomer 2-methyl-4-heptanol, a pheromone of Metamasius hemipterus, using (S)-2-methoxy-2-(1-naphthyl)propionic acid

To investigate the resolution of secondary alcohols using 2-methoxy-2-(1-naphthyl)propionic acid (MalphaNP acid), 2-methyl-4-heptanol, one of the aggregation pheromones of Metamasius hemipterus, was resolved using (S)-MalphaNP acid. As a chiral-resolving agent, MalphaNP acid is superior to 3,3,3-trifluoro-2-methoxy-2-phenylpropionic acid (MTPA) in terms of HPLC separation and NMR shielding. A better separation of diastereomeric MalphaNP esters was observed when n-hexane-THF was used as the eluent for silica gel HPLC. The solvolysis of the diastereomeric MalphaNP esters gave (R)-2-methyl-4-heptanol and its enantiomer; enantiopure (S)-MalphaNP acid was also recovered. In addition, the preferred conformation of the MalphaNP ester was confirmed using methyl (R)-3-hydroxyvalerate as an authentic compound.     

Synthesis and reactions of esters of 3-cyano-2-OXO-5,6-tri(tetra)methylene-1,2-dihydroisonicotinic and 2-amino-3-Ethoxycarbonyl-5,6-tri(tetra)-methyleneisonicotinic acids

Esters of 3-cyano-2-oxo-5, 6-tri (tetra)-methylene-1, 2-dihydroisonicotinic and 2-amino-3-ethoxycarbonyl-5, 6-tri (tetra)methyleneisorticotinic acids have been obtained by the reaction of 2-oxocyclopentyl(hexyl)glyoxylic acid esters with malonic acid derivatives. Boiling the esters containing a tetramethylene ring with 75% sulfuric acid gave hydrolysis of the ester and cyano groups to carboxyl with subsequent decarboxylation at the 3 position and the formation of 2-oxo-5, 6-tetramethylene-1, 2-dihydroisonicotinic acid (2-oxo-1, 2, 5, 6, 7, 8-hexahydroquinoline-4-carboxylic acid).Perm Pharmaceutical Institute, Perm, 614000. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 370–373, March, 1996. Original article submitted July 10, 1995, revision submitted December 26, 1995.     

(R)-2-硫代四氢噻唑-4-羧酸及其酯的合成

L-半胱氨酸盐酸盐与二硫化碳, 氢氧化钠在硝酸铅存在下进行成环反应得到(R)-四氢噻唑-2-硫酮-4-羧酸产率76% , 后者与 醇在硫酸铁水合物催化下反应得到(R)-四氢噻唑-2-硫酮-4-羧酸酯, 产率40～82% .     

含苯并噻唑杂环的α-氨基膦酸二苯酯的合成及生物活性

α氨基膦酸作为氨基酸的含磷类似物,具有广泛的除草［１］、杀菌［２］和植物生长调节活性［３］．最近的研究表明,某些α氨基膦酸衍生物还具有较好的抗植物病毒活性［４,５］．在研究植物病毒抑制剂的过程中,我们发现含苯并噻唑杂环的α氨基膦酸二乙酯类化合物...     

Separation of Enantiomers of 2-(4-hydroxyphenoxy) Propionic Acid and its Esters by HPLC

(±)-2-(4-hydroxyphenoxy) propionic acid and its esters are the important intermediates of the preparation of herbicides such as fenoxaprop, quizalofop-P, fluazifop-P-butyl,fenthiaprop, haloxyfop and so on, especially, (+)-2-(4-hydroxyphenoxy) propionic acid and its esters using as intermediates of the preparation of super-high efficient herbicides.Presently, the separation of the enantiomer of 2-substituted phenoxy propionic acid and its esters had been reported.     

Derivatives of 3-(2-hydroxyethyl)2-benzothiazolinone and related compounds

The reaction of the appropriate 2-benzothiazolinone with 2-chloroethanol or 3-chloropropanol under basic conditions afforded 3-(2-hydroxyethyl or 3-hydroxypropyl)-2-benzothiazolinone and related compounds 1–7. The reaction of the alcohols 1,4, 5 or 7 with potassium hydroxide and excess carbon disulfide furnished the potassium salts of xanthic acid 8–11 which upon oxidation gave the disulfides 12–15. Esters of xanthic acid 16–23 were prepared by the reaction of 8 or 11 with various halogen compounds. Esters of acetic acid 24–28 were prepared by the reaction of the appropriate 2-benzothiazolinone with 2-bromoethyl acetate under basic conditions. Esterification of 1 with various acids afforded the esters 25, 29–32.