摘要:

AbstractThe reaction ofo‐aminobenzenethiol with carbonyl sulfide in the presence of triethylamine afforded an alternate route for the synthesis of 2‐benzothiazolinone (1) in 97–98% yield. The reaction of ammonium thiocarbamate (2) with 2‐chlorocyclohexanone furnished the novel 4,5,6,7‐tetrahydro‐2‐benzothiazolinone (3). 3‐Ethoxy‐2H‐1,4‐benzothiazin‐2‐one (7) was prepared by the reaction ofo‐aminobenzenethiol with diethyl oxalate. Possible pathways and supporting nmr, ir and

ISSN:0022-152X    

DOI:10.1002/jhet.5570230301

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractThis paper describes the synthesis of two 4‐amino‐5H‐pyrimido[5,4‐b]indoles5, 4‐hydrazino‐5H‐pyrimido[5,4‐b]indole6, two 1,2,4‐triazolo[4,3‐c]pyrimido[5,4‐b]indoles8, and tetrazolo[4,5‐c]pyrimido[5,4‐b]indole10. Starting with ethyl 3‐aminoindole‐2‐carboxylate1, 5H‐pyrimido[5,4‐b]indol‐4‐one2was obtained (80%) by condensing with formamide. Reactions of2with phosphorus oxychloride and phosphorus pentasulfide gave respectively, 4‐chloro‐5H‐pyrimido[5,4‐b]indole3(70%) and 5H‐pyrimido[5,4‐b]indole‐4‐thione4(80%). Compound3reacted with amines (morpholine, piperidine) to give the respective 4‐amino‐5H‐pyrimido[5,4‐b]‐indoles5, and compound4reacted with hydrazine to give 4‐hydrazino‐5H‐pyrimido[5,4‐b]indole6(80%). Two hydrazones of6(benzylidene, isopropylidene)7were also prepared (90%). Compound6reacted with formic and acetic acids to give (65–75%) the respective 1,2,4‐triazolo[4,3‐c]pyrimido[5,4‐b]indoles8and with nitrous acid to give tetrazolo[4,5‐c]pyrimido[5,4‐b]indole9(85%). All the

ISSN:0022-152X    

DOI:10.1002/jhet.5570230302

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractThe proton catalyzed reaction of 2,3‐dimethylindole (1) with several arylaldehydes2yields the 6,6′bisindolylarylmethanes5regioselectively. No mechanistic information about the predominant attack of the aldehydes on the indole nucleus is obtained, because the reaction proceeds too fast to control. The electron‐rich aldehydes, 2,4,6‐trimethoxybenzaldehyde and indole‐3‐carbaldehyde, yield exclusively the 6,6′,6″‐trisin‐dolylmethane9. The constitutions of all isolated methanes were elucidated by 400 MHz

ISSN:0022-152X    

DOI:10.1002/jhet.5570230303

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract4,5‐Dihydro‐3H‐naphtho[1,8‐bc]furans4and6which have various substituents (R1and R2) have been synthesized from 8‐oxo‐5,6,7,8‐tetrahydro‐1‐naphthyloxyacetic acids1and3or their ethyl esters2. The reaction of acids1and3with sodium acetate in acetic anhydride gave a mixture of furans4and6and lactones5and7. The ratios of the products were varied according to the types of substituents (R1and R2) in acids1and3. As the substituent R1(R2= hydrogen) in acids1was changed from hydrogen to a methyl, ethyl or isopropyl group, production of furans4became more difficult. However, when a phenyl group was used as the substituent, furan4was obtained in good yield. Similarly, as the substituent R2(R1= hydrogen) in acids1was changed from hydrogen to a methyl, ethyl or isopropyl group, furan formation was more difficult. In contrast, acids3which had electron‐withdrawing substituents such as chlorine, bromine or a nitro group at the 4‐position afforded furans6in good yield. 4,5‐Dihydro‐3H‐naphtho[1,8‐bc]furans4and 4,5‐dihydro‐3H‐naphtho[1,8‐bc]furan‐2‐carbocylic acids8were synthesized from the reaction of esters2and potassium hydroxide in dioxane. When the substituents R1or R2in esters2were varied from hydrogen to a methyl, ethyl or isopropyl group the total yields of fura

ISSN:0022-152X    

DOI:10.1002/jhet.5570230304

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractA convenient synthesis of furo[3,2‐b]pyridine and its 2‐ and 3‐methyl derivatives from ethyl 3‐hydroxypiconate (1) is described. The hydroxy ester1wasO‐alkylated with ethyl bromoacetate or ethyl 2‐bromopropionate to give the diester2aor2b. Cyclization of compound2aafforded ethyl 3‐hydroxyfuro[3,2‐b]pyridine‐2‐carboxylate (3) which in turn was hydrolyzed and decarboxylated to give furo[3,2‐b]pyridin‐3‐(2H)‐one (4a). Cyclization of2bgave the 2‐methyl derivative4b. Reduction of4aand4bwith sodium borohydride yielded the corresponding hydroxy derivative5aand5brespectively, which were dehydrated with phosphoric acid to give furo[3,2‐b]pyridine (6a) and its 2‐methyl derivative (6b). 2‐Acetylpyridin‐3‐ol (8) was converted to the ethoxycarbonylmethyl ether (9) byO‐alkylation with ethyl bromoacetate, which was cyclized to give 3‐methylfuro[3,2‐b]pyridine‐2‐carboxylic acid (10). Decarboxylat

ISSN:0022-152X    

DOI:10.1002/jhet.5570230305

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractNew methods of preparing 2,3‐diaminopyridine (13) from 2‐chloro‐3‐nitropyridine (11) and 3,4‐diaminopy‐ridine (8) from 4‐ethoxy‐3‐nitropyridine hydrochloride (5) have been explo

ISSN:0022-152X    

DOI:10.1002/jhet.5570230306

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractA one‐pot synthesis of the 11H‐dibenzo[b,e]1,4]dioxepin ring system from catechol and ano‐chlorobenzyl chloride is described. Friedel‐Crafts acylation occurs at the 7‐position as shown by X‐r

ISSN:0022-152X    

DOI:10.1002/jhet.5570230307

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract4‐Cyano‐1‐(2,3,5‐tri‐O‐acetyl‐β‐D‐ribofuranosyl)‐5‐methylimidazole (4) and its corresponding 5‐cyano‐4‐methyl substituted isomer (5) have been obtained by ribosylation of 4(5)‐cyano‐5(4)‐methylimidazole (3)viathe mercuric cyanide method or by ribosylation of the trimethylsilyl derivative of3. Treatment of4with methanolic ammonia, ammonium chloride in liquid ammonia and potassium hydrosulfide provided 4‐cyano‐1‐β‐D‐ribofuranosyl‐5‐methylimidazole (6), 1‐β‐D‐ribofuranosyl‐5‐methylimidazole‐4‐carboxamide (2) and 1‐β‐D‐ribofuranosyl‐5‐methylimidazole‐4‐thiocarboxamide (11) respectively. Reaction of6with hydroxylamine afforded the corresponding 4‐carboxamidoxime substituted nucleoside (13) which on catalytic reduction in the presence of ammonium chloride, was transformed into

ISSN:0022-152X    

DOI:10.1002/jhet.5570230308

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

Abstract11,13,15‐Triazasteroidal skeleton with an alkyl group in the D‐ring was synthesized and it was screened for antidepressive activity. Compounds VIIId and XIIa exhibited antireserpine act

ISSN:0022-152X    

DOI:10.1002/jhet.5570230309

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY

摘要:

AbstractAnnelated derivatives of 2‐phenylquinoline, 2‐(2′‐pyridyl)quinoline, and 2‐phenyl‐1,8‐naphthyridine have been prepared where the bridging unit contains from one to four methylene units. The conformational properties of these molecules have been analyzed by1H nmr and uv spectroscopy as well as by pKad

ISSN:0022-152X    

DOI:10.1002/jhet.5570230310

出版商:Wiley‐Blackwell    

年代:1986

数据来源: WILEY