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Biomedical subjects

Peter J Steel

Publications and source records attributed to Peter J Steel.

8 recordsLinked to original sources
PubMed2003

Syntheses of Examples of the 5,6-dihydro-4H-[1,2,3]triazolo[4,5,1-ij]quinoline, 4,5,6,7-tetrahydro[1,2,3]triazolo[4,5,1-jk][1,4]benzodiazepine, and 5,6,7,8-tetrahydro-4H-[1,2,3]triazolo[4,5,1-kl][1]benzazocine ring systems.

Lithiation of 1-vinylbenzotriazole 9 with n-BuLi (2 equiv) generates dianion 10, which upon subsequent reaction with 1,2- and 1,4-diketones affords 14 and 13, representatives of the 5,6-dihydro-4H-[1,2,3]triazolo[4,5,1-ij]quinoline 1 and 5,6,7,8-tetrahydro-4H-[1,2,3]triazolo[4,5,1-kl][1]benzazocine 2 ring systems, respectively. Reactions of dianion 10 with isocyanates give 15a,b, which contain the 4,5,6,7-tetrahydro[1,2,3]triazolo[4,5,1-jk][1,4]benzodiazepine 3 ring system.

Journal Article↗
PubMed2003

Lithiation of 1-chloromethylbenzotriazole: generation and elaboration of benzotriazolyloxiranes.

1-Benzotriazolylchloromethyllithium generated from 1-chloromethylbenzotriazole (1) and LDA reacts with enolizable and nonenolizable ketones to give benzotriazolyloxiranes 2a-g in good yields. The oxiranyllithiums 4a-d generated from 2a-d and n-BuLi at -78 degrees C were trapped by a variety of electrophiles to give oxiranyl derivatives 5a-j in good to excellent yields. Lewis-acid-promoted nucleophilic ring opening of benzotriazolyloxiranes 2a,f,g with allyltrimethylsilane gave the corresponding 1,7-octadien-4-ols 6a-c in 68-75% yield. Hydrolysis of alpha-acylbenzotriazolyloxiranes 5g,h provided 3-hydroxy-1,2-diones 7a and 7b in 73 and 86% yield, respectively.

Journal Article↗
PubMed2002

Novel routes to 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines and 5,6,9,10,11,11a-hexahydro-8H-pyrido[1,2-a]pyrrolo[2,1-c]pyrazines.

Condensation reactions of benzotriazole and 2-(pyrrol-1-yl)-1-ethylamine (1) with formaldehyde and glutaric dialdehyde, respectively, afforded intermediates 2 and 6. Subsequent nucleophilic substitutions of the benzotriazole group in 2 and 6 with Grignard reagents, sodium cyanide, and sodium borohydride gave 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines 3a-e, 4, 5 and 5,6,9,10,11,11a-hexahydro-8H-pyrido[1,2-a]pyrrolo[2,1-c]pyrazines 7a-c, 8, 9, respectively, in good yields.

Molecular Structure↗
PubMed2002

A self-complementary molecular cleft.

Reaction of silver(I) salts with a new octadentate ligand generates a novel self-complementary molecular cleft which forms dimers in the solid state, stabilised by pi-stacking interactions and intermolecular C-H...M interactions.

Journal Article↗
PubMed2002

Convenient preparation of tert-butyl beta-(protected amino)esters.

Refluxing an aldehyde 1 with benzotriazole and benzylcarbamate in the presence of a catalytic amount of p-TsOH gave the corresponding benzyloxycarbonylamino-1-(1-benzotriazolyl)alkane 2 in good yields. Compounds 2 treated with substituted tert-butyl acetates 3 using LDA as a base afford smoothly and under mild conditions the N-2-protected 3-aminoalkanoic esters 4.

Journal Article↗
PubMed2002

Synthesis of 3,4-dihydro-2H-1,3,5-thiadiazines.

3,4-Dihydro-2H-1,3,5-thiadiazines substituted at the 3 and 6 positions were synthesized by treatment of N-substituted N,N-bis(1H-1,2,3-benzotriazol-1-ylmethyl)-amines with thioamides and zinc bromide in dry CH(2)Cl(2) at room temperature for 48-60 h in 48-80% yields.

Journal Article↗
PubMed2002

A novel rearrangement to 1,2,4-triazolo[1,5-a]quinoxalines.

Reactions of benzyl bromide or benzyl cinnamate with N-(benzotriazol-1-ylmethyl)arylimidoyl chlorides (2a,b) in the presence of t-BuOK occur with opening of the benzotriazole ring affording 1,2,4-triazolo[1,5-a]quinoxalines (3a,b). A possible reaction mechanism is discussed.

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