Preparation of alkyl and benzyl fluorides from the corresponding primary amines

Katritzky, Alan R.; Chermprapai, Amornsri; Patel, Ranjan C.

doi:10.1039/c3979000238a

Cited by 14 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4,4',6,6'-Tetraphenyl-1,l '-di-p-tolyl-2,2'-bipyridinium Salt (16). The betaine (6b) (1 g, 2.7 mmol) was added to a solution of bromine (1.6 g, 10 mmol) in CHCl, (45 ml) and heated to reflux immediately.…”

Section: 6-diphenyl-1 -( P-tolyl )Pyridinium-2-dithiocarboxylatementioning

confidence: 99%

“…The betaine (6b) (1 g, 2.7 mmol) was added to a solution of bromine (1.6 g, 10 mmol) in CHCl, (45 ml) and heated to reflux immediately. After 30 min the solvent was evaporated, and the crystalline residue was filtered and washed with ether to yield the title compound (16) (1 g, 7779, m.p. 175-1 80 "C (decomp.…”

Section: 6-diphenyl-1 -( P-tolyl )Pyridinium-2-dithiocarboxylatementioning

confidence: 99%

“…In our betaine, such a reaction at the N-substituent is unlikely and simple dimerisation is likely to occur: indeed dimeric products were formed on heating the 2-carboxy salts (8), but together with varying amounts of simple decarboxylation. Reproducible dimer formation was accomplished by reaction of the carboxy betaine (6b) with bromine, which gave the mixed bromidetribromide (16).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Some novel reactions of pyridinium-2-carboxylate betaines

Katritzky¹,

Cozens²,

Ossana³

et al. 1985

J. Chem. Soc., Perkin Trans. 1

Self Cite

View full text Add to dashboard Cite

Appropriate 2-ethoxycarbonylpyridinium salts are hydrolysed to 1 -aryl-4,6-diphenylpyridinium-2-carboxylate betaines which undergo thermal decarboxylation to afford, in the presence of acids, 1 -aryl-2,4-diphenylpyridinium salts. The intermediate ylides are captured by acid chlorides to yield 2-acylpyridinium salts and by CS, to give dithio analogues of the starting betaines. With bromine, the carboxylate betaine yields a 2,2'-bipyridyl bisquaternary salt.1 -Benzyl-4,6 -dip henylpyrid in ium -2-carboxy late with benzoyl chloride yields 2 -benzoyl-4,6 -diphenylpyridine and benzyl chloride. Benzaldehydes in place of PhCOCI, also gave 2-acylpyridines.The original objective of the present work was to induce aryl migration in intermediates of type (2), related to previously studied intramolecular nucleophilic attacks on N-aryl groups in suitably substituted pyridinium salts which resulted in easy displacement at the @so-carbon atom of the N-aryl group, and transfer to an oxygen,* ~u l p h u r ,~ or nitrogen ' s 4 atom. A r ( 1 ) I VAr ( 3 )While rearrangements (2+(3) were not achieved, several new reactions of the zwitterions (1) were disclosed. Transformations of type (lfi(2) have been reported by several authors, notably Ratts' (capture by RCHO) and Quast6*7 (capture by diazonium salts and by azides), and we now considerably extend the range of this reaction type.2-Ethoxycarbonyl-4,6-diphenylpyrylium tetrafluoroborate (4) reacted with aniline, p-toluidine, and benzylamine under standard conditions 8,9 to give the corresponding 1 -substituted pyridinium salts (5a-c) in high yields. These pyridinium-2-esters (5a-c) were hydrolysed by aqueous sodium hydroxide at ambient temperature to the 1 -substituted 4,6-diphenylpyridinium-2-carboxylate betaines (6a-c) in good yield. The crystalline carboxylate betaines (6a) and (6b) contain water of crystallisation, as shown by a singlet (2H) in their 'H n.m.r. spectra at 6 2.9, and by elemental analysis.' Anhydrous samples could not be obtained; both drying over magnesium sulphate in methylene chloride and attempted recrystallisation caused decomposition.1-Aryl-4,6-diphenylpyridinium-2-carboxylates (6a) and (6b) were converted into the 2-carboxy salts (8a) and (8b) in methylene chloride at 0 "C with tetrafluoroboric acid. The acid tetrafluoroborates were obtained analytically pure, free of water of crystallisation and in good yield. Their i.r. spectra showed the appearance of the BF4-band at 1050 em-' and a shift of the carbonyl stretching band from 1 650 cm-' in (6a) and (6b) to 1 720 em-' in (8a) and (8b).Decarboxylation of the 1 -Substituted 4,6-Diphenylpyridinium-2-carboxylates (6a+).-The 2-carboxy salts (8a) and (8b) are thermally unstable. When recrystallised from ethanol, the G O band at 1 720 cm-' was lost from the i.r. spectra, and elemental analysis confirmed loss of CO,. (5t(10): a, R = Ph; b, R = 4-MeC6H,; c, R = CH,Ph (7): A, X = I; B, X = Br; C, X = C1 (9): A, R' = Ph; R' = Me (11): a, Ar = Ph; b, Ar = p-MeC6H4; c, Ar = p-NO,C,H,; d, Ar = p-CIC,H, Scheme 2. Reagenfs:...

show abstract

Section: 6-diphenyl-1 -( P-tolyl )Pyridinium-2-dithiocarboxylatementioning

confidence: 99%

Section: 6-diphenyl-1 -( P-tolyl )Pyridinium-2-dithiocarboxylatementioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation