摘要:

AbstractSeveral imidazo[4,5‐d]pyridazine nucleosides which are structurally similar to inosine were synthesized. Anhydrous stannic chloride‐catalyzed condensation of persilylated imidazo[4,5‐d]‐pyridazin‐4(5H)one (1) and imidazo[4,5‐d]pyridazine‐4,7(5H,6H)dione (16) with 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose (3) provided (after sodium methoxide deblocking) 6‐β‐D‐ribo furanosylimidazo[4,5‐d]pyridazin‐4(5H)one (5) and 3,6‐di‐(β‐D‐ribofuranosyI)imidazo[4,5‐d]pyridazin‐4‐one (7); and 1‐(β‐D‐ribofuranosyl)imidazo[4,5‐d]pyridazine‐4,7(5H,6H)dione (19) and 1,5 or 6‐di‐(β‐D‐ribofuranosyl)imidazo[4,5‐d]pyridazine‐4,7(5Hor 6H)dione (21), respeeitvely. 4,7‐Diehloro‐1‐β‐D‐ribofuranosylimidazo[4,5‐d]pyridazine (12) and dimethyl 1‐β‐D‐ribofuranosylimidazole‐4,5‐dicarboxylate (26), both prepared from stannic chloride‐catalyzed ribosylations of the corresponding heterocycles, were converted in several steps to 3‐β‐D‐ribo‐furanosy limidazo[4,5‐d]pyridazin‐4(5H)one (14) and nucleosidc19, respectively. Acid‐catalyzed isopropylidenation of mesomeric betaine7or nuclcoside14provided 3‐(2,3‐isopropylidene‐β‐D‐ribofuranosyl)imidazo[4,5‐d]pyrizin‐4(5H)one (31). 1‐β‐D‐Ribofuranosylimidazo[4,5‐d]‐pyr

ISSN:0022-152X    

DOI:10.1002/jhet.5570150101

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractC13Nmr chemical shits of primaquine and chloroquine are reported. The signals are assigned on the basis of substituent effects on benzene shifts, intensities, multiplicities in SFORI) and the comparison with structurally related compounds.

ISSN:0022-152X    

DOI:10.1002/jhet.5570150102

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractThe13C nmr chemical shifts of phenylbutazone, oxyphenbutazone, indomethacin and indole‐3‐acetic acid are reported. The assignments of various carbon resonances are made on the basis of the substitution effects on benzene shifts, multiplicities generated in SFORD spectra, nuclear overhauser enhancement for protonated carbons, and the comparison with analogous compou

ISSN:0022-152X    

DOI:10.1002/jhet.5570150103

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractThe quaternisation of 2‐(methylpyridyl or quinolyl)benz‐X‐azoles mainly leads to the corresponding pyridinium and quinolinium salts, from which polymethine dyes are prepared. The electronic spectra and the methyl protons chemical shifts are briefly disc

ISSN:0022-152X    

DOI:10.1002/jhet.5570150104

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractDe nouveaux systèmes formés d'un hétérocycle azoté à cinq, six ou sept chaînons (pyrazole, pyrimidine ou diazépine) accolé simultanément aux deux cycles A et B d'un dérivé du cholestane par les positions 4, 5 et 6 ont

ISSN:0022-152X    

DOI:10.1002/jhet.5570150105

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractOxidation of 3‐hydroxy‐6‐methyl‐2‐hydroxymethylpyridine with manganese dioxide yielded the corresponding aldehyde, the condensation of which with diethyl bromomalonate furnished hydroxydihydrofuro[3,2‐b]pyridinediearboxylie acid ester. Saponification of the diester with concentrated hydrochloric acid afforded the hydrochloride of 5‐methylfuro[3,2‐b]pyrjdine c

ISSN:0022-152X    

DOI:10.1002/jhet.5570150106

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractA new route was employed to synthesize methyl 6‐ehlorofuro[2,8‐b]pyridine‐2‐earboxylate by eoneurrent dehydrohalogenation and dehydration of 3‐ehloro‐3‐(β,β‐dichloro‐β‐ethoxycar‐bonylelhyl)‐2,6‐piperidinedione usin

ISSN:0022-152X    

DOI:10.1002/jhet.5570150107

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractCondensation of two equivalents of an aromatic cyclic anhydride with an aromatic diamine, or of two equivalents of an aromatic amine with an aromatic bisanhydride, results in the formation of an aromatic bisimide. Thirty‐one such bisimides were prepared. The bisimides in which the two imide groups arc connected by a fully coplanar system show extremely low solubilities and high melting and decomposition temperatures. Many are also strongly colored. It is suggested that these properties may result from intermolecular charge‐transfer effects in the solid slate, giving charge‐transfer pol

ISSN:0022-152X    

DOI:10.1002/jhet.5570150108

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractMono and 1,3‐disubstituted selenoureas react with dimethyl acetylenedicarboxylate to give in high yield substituted 3,4‐dihydro‐4‐oxo‐2H‐1,3‐selenazines whose structures were established by speclros

ISSN:0022-152X    

DOI:10.1002/jhet.5570150109

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY

摘要:

AbstractThe Michael addition of ethyl acetoacetate to benzoquinone, toluquinone, and chlorobenzo‐quinone leads to formation of substituted 5‐hydroxybenzofuran‐3‐earboxylates and linear benzo‐[1,2‐b:4,5‐b']difurans. The previously reported structural proof for the benzodifurans obtained from chlorobenzoquinone and toluquinone, although correct in the conclusion, is shown to be invalid. Proof of the linear benzodifuran structures was obtained by comparison of the uv spectra with authentic angular benzo[1,2‐b:

ISSN:0022-152X    

DOI:10.1002/jhet.5570150110

出版商:Wiley‐Blackwell    

年代:1978

数据来源: WILEY