Synthesis of herbicidal ZJ0273 labeled with tritium and carbon‐14

ZJ0273, propyl 4‐(2‐(4,6‐dimethoxypyrimidin‐2‐yloxy)benzylamino)benzoate, is a broad‐spectrum herbicidal ingredient used for weed control in oilseed rape in China. Two mono‐labeled ZJ0273, propyl 4‐(2‐(4,6‐dimethoxypyrimidin‐2‐yloxy)[phenyl‐3,4,5,6‐³H₄]benzylamino)benzoate (7) and propyl 4‐(2‐(4,6‐dimethoxy[4,6‐¹⁴C₂]pyrimidin‐2‐yloxy)benzylamino)benzoate (12), were synthesized separately from [2,3,4,5,6‐³H₅]phenol in a four‐step yield of 27% and from 4,6‐dichloro‐2‐(methylthio)[4,6‐¹⁴C₂]pyrimidine in a three‐step yield of 54%. In addition, two dual‐labeled analogues of ZJ0273 were prepared by homogeneously mixing tritium‐labeled ZJ0273 (7) in the benzyl ring separately with two carbon‐14‐labeled ZJ0273 (2, 12) in the benzoate ring and the pyrimidine ring. These labeled ZJ0273 could be used as radiotracers in the studies on the metabolism, mode of action, environmental behavior, and fate of ZJ0273. Copyright © 2008 John Wiley & Sons, Ltd.     

Microwave‐assisted synthesis of (RS) methyl‐2‐([2′‐14C]4,6‐dimethoxypyrimidin‐2′‐yloxy)‐2‐phenyl [1‐14C]ethanoate

We report here a facile synthesis of (RS) methyl‐2‐([2′‐¹⁴C]4,6‐dimethoxypyrimidin‐2′‐yloxy)‐2‐phenyl [1‐¹⁴C]ethanoate under microwave irradiation. Copyright © 2006 John Wiley & Sons, Ltd.     

Synthesis of carbon‐14 labeled ZJ0712, a novel strobilurin fungicide

ZJ0712, a broad‐spectrum fungicidal ingredient of strobilurin, exhibits a high protective and curative activity against plant pathogenic fungi. To support the study on its metabolism, residue, environmental behavior, and fate for safety evaluation, two versions of carbon‐14 labeled ZJ0712, methyl (E)‐2‐(2‐((2,5‐dimethylphenoxy)methyl)phenyl)‐3‐methoxy[2‐¹⁴C]acrylate ( 2 ) and methyl (E)‐2‐(2‐((2,5‐dimethyl[phenyl‐U‐¹⁴C₆]phenoxy)methyl)phenyl)‐3‐methoxyacrylate ( 3 ), were synthesized from barium [¹⁴C]carbonate in 6‐step yield of 47% and from 2,5‐dimethyl[phenyl‐U‐¹⁴C₆]phenol in the yield of 91%, respectively.     

Synthesis of deuterium labelled 2‐bromobenzylamine by directed ortho‐metalation chemistry

Directed ortho‐metalation (DoM) strategy has been applied for the development of a short procedure for the regiospecific synthesis of [phenyl‐²H₄]‐2‐bromo‐benzylamine 6 starting from commercially available [phenyl‐²H₅]‐benzoyl chloride 1 . A strong isotope effect was observed during the ortho‐substitution. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis of three isotopically labeled versions and a metabolite of Aurora A kinase inhibitor

Sodium ring‐[¹⁴C]‐4‐[[9‐chloro‐7‐(2,6‐difluorophenyl)‐5H‐pyrimido[5,4‐d][2]benzazepin‐2‐yl]amino]‐benzoate (1A, MLN8054), an Aurora A kinase inhibitor, was synthesized from [¹⁴C]‐cyanamide in two steps in an overall radiochemical yield of 7%. The intermediate, [¹⁴C]‐4‐guanidinobenzoic acid, was prepared by coupling [¹⁴C]‐cyanamide with 4‐aminobenzoic acid. Sodium carboxyl‐[¹⁴C]‐4‐[[9‐chloro‐7‐(2,6‐difluorophenyl)‐5H‐pyrimido[5,4‐d][2]benzazepin‐2‐yl]amino]‐benzoate (1B) was synthesized from carboxyl‐[¹⁴C]‐4‐guanidinobenzoic acid in one step in a radiochemical yield of 35%. [D₄,¹⁵N]‐4‐[[9‐chloro‐7‐(2,6‐difluorophenyl)‐5H‐pyrimido[5,4‐d][2]benzazepin‐2‐yl]amino]‐benzoic acid (1C) was synthesized from [¹⁵N₂]‐cyanamide and [D₄]‐4‐aminobenzoic acid in two steps in an overall yield of 37%. The major metabolite, β‐acyl glucuronide of 4‐[[9‐chloro‐7‐(2,6‐difluorophenyl)‐5H‐pyrimido[5,4‐d][2]benzazepin‐2‐yl]amino]‐benzoic acid (14), was synthesized from D‐glucuronic acid in three steps in an overall yield of 1%. The key intermediate for synthesis of glucuronide was prepared by HATU catalyzed coupling of 4‐[[9‐chloro‐7‐(2,6‐difluorophenyl)‐5H‐pyrimido[5,4‐d][2]benzazepin‐2‐yl]amino]‐benzoic acid with allyl glucuronate. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of C‐14 and C‐13, H‐2‐labeled IKK inhibitor: [14C] and [13C4,D3]‐N‐(6‐chloro‐7‐methoxy‐9H‐pyrido[3,4‐b]indol‐8‐yl)‐2‐methyl‐3‐pyridinecarboxamide

[¹⁴C]‐N‐(6‐Chloro‐7‐methoxy‐9H‐pyrido [3,4‐b]indol‐8‐yl)‐2‐methyl‐3‐pyridinecarboxamide (5B ), an IKK inhibitor, was synthesized from [¹⁴C]‐barium carbonate in two steps in an overall radiochemical yield of 41%. The intermediate, [carboxyl‐¹⁴C]‐2‐methylnicotinic acid, was prepared by the lithiation and carbonation of 3‐bromo‐2‐methylpyridine. [¹³C₄,D₃]‐N‐(6‐chloro‐7‐methoxy‐9H‐pyrido [3,4‐b]indol‐8‐yl)‐2‐methyl‐3‐pyridinecarboxamide (5C ) was synthesized from [1,2,3,4‐¹³C₄]‐ethyl acetoacetate and [D₄]‐methanol in six steps in an overall yield of 2%. [¹³C₄]‐2‐methylnicotic acid, was prepared by condensation of [¹³C₄]‐ethyl 3‐aminocrotonate and acrolein, followed by hydrolysis with lithium hydroxide. Copyright © 2006 John Wiley & Sons, Ltd.     

Design,synthesis, and cytotoxic evaluation of novel furo[2,3‐b]quinoline derivatives

A number of novel furo[2,3‐b]quinoline derivatives were designed and synthesized by introducing benzyl ether, benzoate, and benzenesulfonate to 6‐position of furo[2,3‐b]quinoline and their chemical structures were confirmed by ESI‐MS, ¹H NMR, and ¹³C NMR spectra. All target compounds were evaluated in vitro against four human cancer cell lines (HCT‐116, MCF‐7, U2OS, and A549) by MTT method. Cytotoxic assay showed that compounds 8a , 8e , 10a , 10b, and 10c exhibited more potent cytotoxicities compared to 2‐bromine‐6‐hydroxy‐furo‐[2,3‐b]quinoline ( 7 ). Compound 10c exhibited higher antiproliferative activity (IC₅₀ values ranging from 4.32 to 24.96 μm ) against four human cancer cell lines (HCT‐116, MCF‐7, U2OS, and A549) and weak cytotoxicity on normal cell HL‐7702, which suggested that 10c might be an ideal anticancer candidate. Compounds 8a , 10a , 10b showed good selectivities to MCF‐7 and HCT‐116, which could be considered as ideal selective candidates for further study. The SARs showed that the introduction of the benzyl ether and benzenesulfonate could significantly improve cytotoxicities, while the benzoate failed to enhance potency obviously.     

疟疾防治药物的研究——Ⅹ.2,4-二氨基-6-N1,N2-二取代肼基-喹唑啉类衍生物的合成及其抗疟作用

本文报道了2,4-二氨基-6-N¹,N²-二取代肼基-喹唑啉类衍生物的合成及其抗疟活性的研究。这类化合物的合成是以2,4-二氨基6-取代苄基氨基-喹唑啉为原料经亚硝化、还原成为2,4-二氨基6-(N¹-取代苄基)—肼基喹唑啉,再与相应的醛缩合而成。此类化合物经伯氏鼠疟原虫抑制性治疗初筛表明有少数具有一定的效果。有11个化合物经约氏鼠疟原虫—斯氏按蚊系统病因性初筛有效。其中化合物Ⅱ_1,7,8,11,15和Ⅲ₁口服2.5mg/kg,连续3天,可使受试小鼠全部得到保护。     

Amino Acid Derivatives,Part 4: Synthesis and Anti‐HIV Activity of New Naphthalene Derivatives

A new series of 2‐(naphthalen‐2‐yloxy)‐N‐[(aryl‐5‐thioxo‐4,5‐dihydro‐1H‐1,2,4‐triazol‐3‐yl)methyl] acetamides 5a–f was synthesized from naphthalene‐derived glycine derivative 2 via the hydrazinoacetamide analogs 4a–f . Alternatively, treatment of 4a with H₂SO₄ afforded 2‐(naphthalen‐2‐yloxy)‐N‐((5‐(phenylamino)‐1,3,4‐thiadiazol‐2‐yl)methyl) acetamide 6a . Alkylation or sulphonylation of 5a afforded the S‐alkylated derivatives 7 and 8 , respectively. Interestingly, treatment of 3 with methoxide ion gave the triazine derivative 9 . The synthesized compounds have been screened for their inhibitory activity against HIV‐1 and HIV‐2 in MT‐4 cells. However, 7 was found to be the potent inhibitor in vitro for the replication of HIV‐1 (EC₅₀ = 0.20 μg/mL), suggesting a new lead in the development of an antiviral agent.     

Synthesis of [2H3]‐labelled sulfamethoxazole and its main urinary metabolites

Sulfamethoxazole was labelled at positions 3, 5, and 4′ by H/D exchange in a mixture of 5% ²H₂SO₄ and 95% ²H₂O (v/v) under reflux for 72h with good isotope incorporation and acceptable yield. Subsequently, [²H₃]‐sulfamethoxazole‐N₁‐glucuronide and [²H₃]‐N₄‐acetyl‐sulfamethoxazole were synthesized. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis of deuterium and C‐13‐labelled ethyl glycolate and their subsequent use in the synthesis of labelled analogues of the DNA adduct O6‐carboxymethyl‐2′‐deoxyguanosine

The adduct O⁶‐carboxymethyl‐2′‐deoxyguanosine (O⁶CMdG) is of importance as it has been previously linked to high red meat diet in humans, and as yet, a liquid chromatography‐mass spectrometry (LC‐MS) method has not been developed due to lack of appropriate standards. The synthesis of the deuterated and C‐13 analogues required the use of [²H₂]‐ and [¹³C₂]ethyl glycolate to label the carboxymethyl moiety of O⁶CMdG. [²H₂]Ethyl glycolate was synthesised via acid hydrolysis of ethyl diazoacetate using deuterated solvents (59% yield), whilst [¹³C₂]ethyl glycolate was synthesised from [¹³C₂]glycine in a three‐step procedure (35% yield). The labelled ethyl glycolates were then used to synthesise [²H₂]‐ and [¹³C₂]O⁶CMdG for future use as internal standards in the LC‐MS analysis of biological samples. Copyright © 2011 John Wiley & Sons, Ltd.     

Evaluation of New Indole and Bromoindole Derivatives as pp60c‐Src Tyrosine Kinase Inhibitors

A series of N‐benzyl‐indole‐3‐imine‐, amine derivatives and their 5‐bromo congeners were synthesized and their biological activity were evaluated against the pp60^c‐Src tyrosine kinase target. To afford the imine derivatives, aldehydes were reacted with substituted benzylamines and the corresponding amine derivatives were obtained by NaBH₄ reduction of these imines. Except insoluble N‐benzyl‐indole‐3‐imine derivatives, all the derivatives showed some activity against the kinase target. Screening of these compounds for their biological activity revealed that among N‐benzyl‐indole derivatives, those bearing 5‐bromo substitution have the enhanced potency, where the amine derivatives were more active than imines.     

Expeditious syntheses of stable and radioactive isotope‐labeled anticonvulsant agent,JNJ‐26990990, and its metabolites

Syntheses of stable and radioactive isotope‐labeled anticonvulsant agent, JNJ‐26990990, that is, N‐(benzo[b]thien‐3‐ylmethyl)‐sulfamide and its metabolites are described. [¹³C¹⁵N]Benzo[b]thiophene‐3‐carbonitrile was first prepared by coupling of 3‐bromo‐benzo[b]thiophene with [¹³C¹⁵N]‐copper cyanide. The resultant [¹³C¹⁵N]benzo[b]thiophene‐3‐carbonitrile was reduced with lithium aluminum deuteride to give [¹³CD₂¹⁵N]benzo[b]thiophen‐3‐yl‐methylamine; which was then coupled with sulfamide to afford [¹³CD₂¹⁵N]‐N‐(benzo[b]thien‐3‐ylmethyl)‐sulfamide, the stable isotope‐labeled compound with four stable isotope atoms. Direct oxidation of [¹³CD₂¹⁵N]‐N‐(benzo[b]thien‐3‐ylmethyl)‐sulfamide with hydrogen peroxide and peracetic acid gave the stable isotope‐labeled sulfoxide and sulfone metabolites. On the other hand, radioactive ¹⁴C‐labeled N‐(benzo[b]thien‐3‐ylmethyl)‐sulfamide was prepared conveniently by sequential coupling of 3‐bromo‐benzo[b]thiophene with [¹⁴C]‐copper cyanide, reduction of the carbonitrile to carboxaldehyde, and reductive amination with sulfamide.     

Identification of unexpected unlabeled N,N‐dimethylamide formation in the synthesis of deuterated fragment of ribociclib by a HATU‐mediated coupling reaction

Starting from N,N‐dimethylamine and D₂O, deuterated fragment of ribociclib was synthesized for use as a mass spectroscopy internal standard. Furthermore, systematic studies on D₀ (unlabeled material) formation during the amidation reaction were performed, leading to the identification of a coupling reagent, HATU (O‐(7‐azabenzotriazol‐1‐yl)‐N,N,N′,N′‐tetramethyluronium hexafluorophosphate), as main cause. Finally, an alternative route was designed using EDCI/HOBT as coupling reagents to produce the desired deuterated compound without D₀ residue.     

A facile synthesis of [14C]pyrithiobac‐sodium

Condensation of thiourea 1 with diethyl malonate 2 in the presence of sodium methoxide furnished 4,6‐dihydroxy‐2‐mercaptopyrimidine 3 . Compound 3 on methylation with diazomethane followed by oxidation with H₅IO₆/CrO₃ in ethyl acetate gave 4,6‐dimethoxy‐2‐methylsulphonylpyrimidine 5 . Compound 5 on condensation with 2‐mercapto‐6‐chlorobenzoic acid in the presence of a phase transfer catalyst, tetrabutylammonium bromide and sodium carbonate gave the title compound – pyrithiobac‐sodium 6 with an overall yield of > 35% starting from thiourea. Following the above standardized procedure, using [¹⁴C]‐thiourea in lieu of thiourea, ¹⁴C labelled product 6 , was synthesized with an overall radiochemical yield > 30% (with respect to [¹⁴C]‐thiourea) for further evaluations of environmental fate of 6 , in soils and plants. Copyright © 2006 John Wiley & Sons, Ltd.     

Oestrogenic activity of benzyl salicylate,benzyl benzoate and butylphenylmethylpropional (Lilial) in MCF7 human breast cancer cells in vitro

Benzyl salicylate, benzyl benzoate and butylphenylmethylpropional (Lilial) are added to bodycare cosmetics used around the human breast. We report here that all three compounds possess oestrogenic activity in assays using the oestrogen‐responsive MCF7 human breast cancer cell line. At 3 000 000‐fold molar excess, they were able to partially displace [³H]oestradiol from recombinant human oestrogen receptors ERα and ERβ, and from cytosolic ER of MCF7 cells. At concentrations in the range of 5 × 10^?5 to 5 × 10^?4 m , they were able to increase the expression of a stably integrated oestrogen‐responsive reporter gene (ERE‐CAT) and of the endogenous oestrogen‐responsive pS2 gene in MCF7 cells, albeit to a lesser extent than with 10^?8 m 17β‐oestradiol. They increased the proliferation of oestrogen‐dependent MCF7 cells over 7 days, which could be inhibited by the antioestrogen fulvestrant, suggesting an ER‐mediated mechanism. Although the extent of stimulation of proliferation over 7 days was lower with these compounds than with 10^?8 m 17β‐oestradiol, given a longer time period of 35 days the extent of proliferation with 10^?4 m benzyl salicylate, benzyl benzoate or butylphenylmethylpropional increased to the same magnitude as observed with 10^?8 m 17β‐oestradiol over 14 days. This demonstrates that benzyl salicylate, benzyl benzoate and butylphenylmethylpropional are further chemical components of cosmetic products which give oestrogenic responses in a human breast cancer cell line in culture. Further research is now needed to investigate whether oestrogenic responses are detectable using in vivo models and the extent to which these compounds might be absorbed through human skin and might enter human breast tissues. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of deuterium labeled phenethylamine derivatives

The synthesis of a series of five deuterium labeled phenethylamine derivatives, 4‐bromo‐2,5‐[²H₆]‐dimethoxyphenethylamine (2C‐B), 4‐chloro‐2,5‐[²H₆]‐dimethoxyphenethylamine (2C‐C), 2,5‐[²H₆]‐dimethoxy‐4‐iodophenethylamine (2C‐I), 2,5‐[²H₆]‐dimethoxy‐4‐ethylthiophenethylamine (2C‐T‐2) and 2,5‐[²H₆]‐dimethoxy‐4‐n‐propylthiophenethylamine (2C‐T‐7) from 1,4‐[²H₆]‐dimethoxybenzene is described. The isotopically labeled compounds are used as internal standards in gas chromatography‐mass spectrometry (GC‐MS) assays. Copyright © 2006 John Wiley & Sons, Ltd.     

13C‐ and 14C‐labelling of N‐[1‐(4‐chlorophenyl)‐1H‐pyrrol‐2‐yl‐methyleneamino] guanidinium acetate

N‐[1‐(4‐chlorophenyl)‐1H‐pyrrol‐2‐yl‐¹³C₄‐methyleneamino]guanidinium acetate has been synthesized by a four‐step procedure. This involved reduction of the Weinreb amide N,N′‐dimethyl‐N,N′‐dimethyloxybutane‐1,4‐diamide‐1,2,3,4‐¹³C₄ by Dibal‐H to give the corresponding unstable dialdehyde which is reacted in situ with 4‐chloroaniline to form 1‐(4‐chlorophenyl)‐1H‐pyrrole‐¹³C₄. This pyrrole analogue underwent a Vilsmeyer acylation with POCl₃/DMF followed by final reaction with aminoguanidine bicarbonate to produce the desired labelled compound with 99% atom ¹³C. By using DMF [α‐¹⁴C] a radio‐labelled analogue was synthesized with a specific activity of 60 mCi/mmol. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis of deuterium labeled standards of 5‐methoxy‐N,N‐dimethyltryptamine (5‐Meo‐DMT)

The Batcho‐Leimgruber strategy was employed to synthesize 5‐[²H₃]‐methoxy‐1 H‐indole 4 from commercially available 5‐hydroxy‐2‐nitrotoluene 1 and CD₃I. Compound 4 was treated with oxalyl chloride, dimethylamine and lithium aluminum hydride to yield 5‐[²H₃]‐methoxy‐N,N‐dimethyltryptamine 6 . Copyright © 2006 John Wiley & Sons, Ltd.     

Synthesis of 3,7,8‐15N3‐N1‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin

3,7,8‐¹⁵N₃‐N¹‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin was synthesized from the oxidation of 1,7,NH₂‐¹⁵N₃‐8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine with 2 equivalents of Ir(IV) in pH 4.5 potassium phosphate buffer. The synthesis of 1,7,NH₂‐¹⁵N₃‐8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine started with bromination of 1,7,NH₂‐¹⁵N₃‐2′‐deoxyguanosine. The resulting 1,7,NH₂‐¹⁵N₃‐8‐bromo‐7,8‐dihydro‐2′‐deoxyguanosine reacted with sodium benzyloxide to afford 1,7,NH₂‐¹⁵N₃‐8‐benzyloxy‐7,8‐dihydro‐2′‐deoxyguanosine. Subsequent catalytic transfer hydrogenation of 1,7,NH₂‐¹⁵N₃‐8‐benzyloxy‐7,8‐dihydro‐2′‐deoxyguanosine with cyclohexene and 10% Pd/C yielded 1,7,NH₂‐¹⁵N₃‐8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine. Purification of 3,7,8‐¹⁵N₃‐N¹‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin was first carried out on a C18 column and the product was further purified on a graphite column. ESI‐MS was used to confirm the identity and to determine the isotopic purity of all the labeled compounds. The isotopic purity of 3,7,8‐¹⁵N₃‐N¹‐(β‐D‐erythro‐pentofuranosyl)‐5‐guanidinohydantoin was 99.4 atom% based on LC‐MS measurements. Copyright © 2003 John Wiley & Sons, Ltd.