摘要:

AbstractThe mass spectra of furoxans have large NO+peaks due to the fragmentation of the ring system at C‐N and N‐O bonds. Cleavage of the substituents and to a smaller extent ring fission at C3‐C4account for other ion peaks. The spectra are sufficiently characteristic to serve for the identification of these compounds. The related furazans give different fragmentation patterns because carbon‐carbon cleavage predo

ISSN:0022-152X    

DOI:10.1002/jhet.5570010201

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractA series of new 9‐acridanylmethyl ketones has been prepared by the 9, 10‐addition of the sodium derivatives of a number of ketones to acridine. The 9‐acridanylmethyl ketones were dehydrogenated to the corresponding 9‐acridinylmethyl ketones by either acidic ferric chloride or lead tetraacetate. A route of more limited utility for the synthesis of 9‐acridinylmethyl ketones involves the acylation of 9‐acridinylmethyllithium with certain esters. The attempted ketonic cleavage of α‐(9‐acridinyl)‐β‐ketoesters such as ethyl α‐(9‐acridinyl)isonicotinoylacetate and ethyl α‐(9‐acridinyl)benzoylacetate is an unsatisfactory method for obtaining the corresponding 9‐acridinylmethyl ketones since these ketones are cleaved to 9‐methylacridine unde

ISSN:0022-152X    

DOI:10.1002/jhet.5570010202

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractThe advent of large liquid scintillation counters has created a need for a secondary solute which is more soluble in organic solvents than is 2,2′‐p‐phenylenebis(5‐phenyl‐oxazole) (POPOP, I or II, R‐substituents = H), the preferred secondary solute for small

ISSN:0022-152X    

DOI:10.1002/jhet.5570010203

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractThe Friedel‐Crafts acylation of six phenol ethers with 2, 5‐diphenylfuran‐3, 4‐dicarbonyl chloride and with 2, 5‐dimethylfuran‐3, 4‐dicarbonyl chloride yielded 2, 5‐di‐R‐3, 4‐diaroyl‐furans or cyclic diketones. 2,5‐Diphenylfuran‐3,4‐dicarboxylic acid anhydride reacted with th

ISSN:0022-152X    

DOI:10.1002/jhet.5570010204

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractThe synthesis of a number of 3‐chloroflavones by a new method, involving reaction of arylmagnesium bromides with 3,4‐dichlorocoumarins, is described. The synthesis of 2‐chloro‐7‐methyl‐11H‐benzofuro[3,2‐b] [1)benzopyran‐11‐on

ISSN:0022-152X    

DOI:10.1002/jhet.5570010205

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractThe structure of 2‐amino‐5‐(3‐anilinopropyl)‐6‐methyl‐4‐pyrimidinol (II), an inhibitor of both dihydrofolic reductase and thymidylate synthetase, has been modified by replacement of the 2‐amino group by hydrogen or the 4‐hydroxyl group by hydrogen, mercapto or amino. Enzymic evaluation showed that 5‐(3‐anilinopropyl)‐2,4‐diamino‐6‐methyl‐pyrimidine was a 170‐fold more effective inhibitor of dihydrofolic reductase than thymidylate synthetase. This specificity is due to the fact that replacement of the 4‐hydroxyl group of II with 4‐amino enhances binding to dihydrofolic reductase by 350‐fold, but binding to thymidylate synthetase is unchanged. No significant cross‐over specificity was noted with the six compounds studied.Replacement of the 4‐hydroxyl group of II by hydrogen gave a compound (XVII) that was a slightly more effective inhibitor of dihydrofolic reductase than II, but was slightly less effective on thymidylate synthetase. Binding to dihydrofolic reductase and to thymidylate synthetase could be increased by 17‐fold and 5‐fold, respectively, by replacement of the 4‐hydroxyl group of II by 4‐mercapto (XVI). It was concluded that the mode of binding in the N‐3 and 4‐hydroxyl region of II was not the same for the two enzymes.Synthesis of the 2‐amino‐, the 4‐hydroxy‐ and the 4‐mercaptopyrimidyl analogs of II are described. Also described are the partial purification of and assays for dihydrofolic reductase and thymid

ISSN:0022-152X    

DOI:10.1002/jhet.5570010206

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractSix analogs of 2‐amino‐5‐(3‐anilinopropyl)‐6‐methyl‐4‐pyrimidinol (II) with modifications in the anilino group have been synthesized in order to shed light on the mode of binding of the anilino group to dihydrofolic reductase and thymidylate synthetase. Replacement of the anilino group of II withn‐butylamino (XI) led to great decrease in binding, indicating that the anilino group did not bind to these enzymes in the protonated form. Replacement of the anilino group of II with benzyl gave a compound (XIIb) which was a 26‐fold and 1.5‐fold better inhibitor of dihydrofolic reductase and thymidylate synthetase, respectively; these results indicated that the NH portion of the anilino group contributed less to the enzyme binding than did the benzene ring, and that the latter probably was bound as an electron acceptor in a charge‐transfer complex to an electron‐rich locus on the enzyme. Further evidence was also obtained that the benzene ring was complexing as an electron acceptor by placement of electron‐donating or electron‐withdrawing groups on thep‐positions of anilino group, and by N

ISSN:0022-152X    

DOI:10.1002/jhet.5570010207

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractThe conformations of one dihydro‐1,3‐benzoxazine and two dihydro‐1,3‐naphthoxazines were studied by calculating and measuring their dipole moments.A “semi‐chair” form with a quasi‐axial position of the N‐substituent was found to

ISSN:0022-152X    

DOI:10.1002/jhet.5570010208

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

Abstractα‐Hydroxy‐α‐methyl ketones react with ammonia and aromatic aldehydes in the presence of calcium chloride and ammonium chloride to yield 2‐aryl‐3

ISSN:0022-152X    

DOI:10.1002/jhet.5570010209

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY

摘要:

AbstractA series of 4‐mercaptocinnolines (4) monosubstituted with halogen in the benzenoid ring was obtained when the corresponding 4‐hydroxycinnolines were treated with phosphorus pentasulfide in either pyridine or toluene. On prolonged heating in either or the two solvents, the halogen atom in 6‐chloro‐ and 6‐bromo‐4‐hydroxycinnoline was simultaneously substituted with a mercapto group, thus yielding 4,6‐dimercaptocinnoline. Nucleophilic substitution of the halogen atom was also observed in the reaction of 6‐fluoro‐ and 7‐fluoro‐4‐hydroxycinnoline, while 8‐halo‐4‐hydroxycinnoline gave exclusively 8‐halo‐4‐mercapto‐cinnoline. From the reaction of 5‐halo‐4‐hydroxycinnoline the only identified products were 5‐halo‐4‐mercaptocinnolines. Previously unknown 4‐hydroxycinnolines were synthesized. 4‐Alkylmercaptocinnolines and 4,6‐dialkylmercaptocinnolines of pharmacological interest were prepared from the parent me

ISSN:0022-152X    

DOI:10.1002/jhet.5570010210

出版商:Wiley‐Blackwell    

年代:1964

数据来源: WILEY