A Convenient Preparation of Pyrophosphoryl Chloride and Its Use in Vilsmeier Formylation Reactions

Cheung, Gi K.; Downie, Ian M.; Earle, Martyn J.; Heaney, H.; Matough, M. F. S.; Shuhaibar, K. F.; Thomas, Deborah A.

doi:10.1055/s-1992-21272

Cited by 23 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…35 The two-carbon electron-rich alkene required to form the 3,4-carbons of the quinolinium salt can be derived in a wide variety of ways and those studied to date will be delineated below. We had earlier observed that vinyl acetate undergoes bis-formylation and cyclisation very readily to give the unexpected HETEROCYCLES, Vol.…”

Section: Methodsmentioning

confidence: 99%

“…35 Whenever a methyl rather than a methylene derivative is employed the product is derived via bis-formylation to give a useful aldehyde derivative. Thus 3,5dinitrotoluic acid is transformed into 2-methyl-5,7-dinitroisoquinol-1-one on treatment with DME/POC& (Scheme 14).37" a similar way homophthalic acid and its heteroaromatic analogues yield N-methylisoquinol-1-one-4-carboxylic 552 HETEROCYCLES, Vd.…”

Section: The Synthesis Of Isopuinolines and Other [El-fused Pyridinesmentioning

confidence: 99%

“…35,NO. The synthesis of pyridines and condensed pyridines using V'ismier reagents has become an imponant synthetic tool particularly to the pharmaceutical industry. 35,NO. The synthesis of pyridines and condensed pyridines using V'ismier reagents has become an imponant synthetic tool particularly to the pharmaceutical industry.…”

mentioning

confidence: 99%

See 2 more Smart Citations

The Synthesis of Pyridines, Quinolines and Other Related Systems by the Vilsmeier and the Reverse Vismeier Method

Meth‐Cohn¹

1993

HETEROCYCLES

133

View full text Add to dashboard Cite

Dedicated to the ever youthful Ted Taylor on his 70th birthday AbsIract -Quinolines, pyridines, thienopyridines, quinolones, isoquinolones, nophthyridines and related systems can be made efticiently from acylamides under Vilsmeier conditions. This review focusses on the application of both the Vilsmeier and the Reverse Vilsmeier approach. In the former method the acylamide becomes a nucleophile and is the source of the nitrogenand the 2.3-carbons of the resulting heterocycle while in the latter the acylamide reacts as an electrophile which yields the product heterocycle by reaction with an electron-rich alkene or its equivalent. This 'alkene' can be an enatnine, a vinyl ester, an amide, or a masked nucleophilic alkene such as a ketone or an 'active'methyl or methylene group as in an asubstituted acetic acid .

show abstract

Section: Methodsmentioning

confidence: 99%

Section: The Synthesis Of Isopuinolines and Other [El-fused Pyridinesmentioning

confidence: 99%

See 1 more Smart Citation

The Synthesis of Pyridines, Quinolines and Other Related Systems by the Vilsmeier and the Reverse Vismeier Method

Meth‐Cohn¹

1993

HETEROCYCLES

133

View full text Add to dashboard Cite

show abstract

“…35 (Schema 11) und kann daher die Supersäure abpuffern, so dass die Protonierung der Ameisensäure unterbleibt und damit in dem Medium kein aktives Formylierungsmittel vorhanden ist, womit erklärt werden kann, dass in Acetonitril die Formylierung von Resorcindimethylether ausbleibt. Interessanterweise bildet 39 mit N,N-Dimethylformamid ein zu den Salzen 36, 37 analoges Addukt 40, das ein höheres Formylierungsvermögen besitzt als das klassische Vilsmeier-Haack-Reagenz (Schema 14) [28].…”

Section: Aromatunclassified

Zur Formylierung von Hydroxy- und Alkoxyaromaten mit Ameisensäure

Kantlehner

Ziegler

Mezger

et al. 2019

Zeitschrift Für Naturforschung B

View full text Add to dashboard Cite

By treatment of ethers of phenol, resorcinol, 2-napththol, alkylanisoles 10, 13, 15, 17, 20, 22, 24, 28 with formic acid/borontrichloride the aromatic aldehydes 11, 14, 16, 18, 21, 23, 25, 26, 29 can generally be prepared in low yields. The formylation reactions proceed between −20 and −10°C within 20 min in 1,2-dichloroethane, chlorobenzene, or methylene chloride as solvents when formic acid and borontrichloride are used in excess [molar ratio of aromatic compound to HCOOH to BCl3 = 1:1.2–1.7:1.6–1.8]. The more strongly activated 3,5-dimethoxyphenol (33) is formylated by formic acid/borontrichloride to give the aldehyde 34 with an acceptable yield. The reactions of resorcinol dimethylether with formic acid in the presence of super acids (mainly trifluormethansulfonic acid) in chlorobenzene or nitromethane deliver the aldehyde 21 only in small amounts.

show abstract

“…Bis-1,1'-(3,4-dihydroisoquinolines) unsubstituted in position 3 have been previously obtained using a Bischler-Napieralski reaction by the action of POCl 3 in acetonitrile [3] or Tf 2 O in the presence of 4-N,N-dimethylaminopyridine [4] on the corresponding oxamide. A method is known for the Ullman preparation [2] of bis-1,1'-isoquinolines while 3,4-dihydro derivatives are not formed under these conditions and they are rather inaccessible compounds.…”

mentioning

confidence: 99%

Symmetrical and Unsymmetrical Bis-1,1′-(3,4-dihydroisoquinolines)

Глушков

Karmanov

Shklyaev

2005

Chem Heterocycl Compd

View full text Add to dashboard Cite

Shklyaev3,3,-Dialkyl-1-cyano-3,4-dihydroisoquinolines were prepared by Beckmann defragmentation of ethyl α-(3,3-dialkyl-3,4-dihydroisoquinol-1-yl)-α-hydroximinoacetates and they take part in a Ritter reaction to form substituted bis-1,1'-(3,4-dihydroisoquinolines).As heterocyclic analogs of 1,1'-binaphthyl systems, bis-1,1'-isoquinolines are promising ligands for the preparation of metallocomplex catalysts since coordination with a metal is possible at the nitrogen atoms [1]. A method is known for the Ullman preparation [2] of bis-1,1'-isoquinolines while 3,4-dihydro derivatives are not formed under these conditions and they are rather inaccessible compounds. Bis-1,1'-(3,4-dihydroisoquinolines) unsubstituted in position 3 have been previously obtained using a Bischler-Napieralski reaction by the action of POCl 3 in acetonitrile [3] or Tf 2 O in the presence of 4-N,N-dimethylaminopyridine [4] on the corresponding oxamide. In the current work we propose a route to bis-1,1'-(3,4-dihydroisoquinolines) which is based on the Ritter reaction [5,6].A second order Beckmann rearrangement [7,8] of ethyl α-(3,3-dialkyl-3,4-dihydroisoquinol-1-yl)-αhydroximinoacetates 1a-c using the method [9, 10] gave the nitriles 2a-c. Despite the simplicity it should be noted that the indicated method is poorly reproducible in our hands, the yields of the products 2 differing markedly from one experiment to another.The nitrile 2a was also prepared by the dehydration of 3,3-dimethyl-3,4-dihydroisoquinolylaldoxime 3 [11] in refluxing xylene using a known method [12] (see Experimental section. The hydrochloride 3.HCl has been reported before [13]).The Ritter reaction of nitriles 2a-c and carbinols 4a-c (stirring the reagents in a mixture of toluene and conc. H 2 SO 4 at 20°C) gave 42-71% yields of compounds 5a-e (Tables 1 and 2). According to this scheme another combination of nitrile and carbinol is possible which leads to both symmetrical and unsymmetrical bis-1,1'-(3,4-dihydroisoquinolines) 5. Compound 5c was also prepared in somewhat lower yield (37%) by the condensation of nitrile 2b with veratrole and isobutylene oxide using method [14] (Scheme 1).A feature of the 1 H NMR spectrum of compound 5b is the small shift of the H-8 signal of the 6,7-dimethoxy-substituted ring to high field by about 0.2 ppm when compared with the H-8 signal of 6,7-dimethoxy-1,3,3-trimethyl-3,4-dihydroisoquinoline [14] and this is due to the anistropic effect of the neighboring 3,4-dihydroisoquinoline fragment. A similar high field shift caused by a benzene ring has previously been observed by us in the case of 6,7-dimethoxy-3,3-dimethyl-1-phenyl-3,4-dihydroisoquinoline [14].0009-3122/05/4104-0475©2005 Springer Science+Business Media, Inc. nitrile 2b (0.3 g, 1.23 mmol) and carbinol 4a (0.2 ml, 1.25 mmol) in toluene (20 ml) was added to conc. H 2 SO 4 (10 ml) and the mixture obtained was stirred for 2 h at 20°C and poured into water (100 ml).The aqueous layer was separated, washed with toluene (15 ml) and NH 4 OH (25%) was then added to pH ~ 8. The product was ext...

show abstract

A Convenient Preparation of Pyrophosphoryl Chloride and Its Use in Vilsmeier Formylation Reactions

Cited by 23 publications

References 0 publications

The Synthesis of Pyridines, Quinolines and Other Related Systems by the Vilsmeier and the Reverse Vismeier Method

The Synthesis of Pyridines, Quinolines and Other Related Systems by the Vilsmeier and the Reverse Vismeier Method

Zur Formylierung von Hydroxy- und Alkoxyaromaten mit Ameisensäure

Symmetrical and Unsymmetrical Bis-1,1′-(3,4-dihydroisoquinolines)

Contact Info

Product

Resources

About