4//-Quinolizine

Furazano[3,4-d]pyrimidine, 7-amino-synthesis, 6, 729 UV spectra, 6, 713 Furazanopyrimidines amine synthesis from, 5, 591 synthesis, 6, 418 Furazano[3,4-d]pyrimidines nucleophilic attack, 6, 719 nucleophilic substitution, 6, 713 reduction, 6, 402 7-substituted reactions, 6, 722 Furazano[3,4-a]quinolizines synthesis, 6, 730... 

H-Quinolizine, 2-(4-chlorophenylimino)-applications, 2, 569 4H-Quinolizine, cyanotriphenyl-synthesis, 4, 469 Quinolizines reactions, 2, 547 Quinolizines, dihydroreactions, 2, 547 4H-Quinolizines oxidation, 2, 547 synthesis, 2, 568 Quinolizine-2-thiones reactions, 2, 545 synthesis, 2, 544 Quinolizine-4-thiones... 

Quinolizinium salts, 2,4,6-trimethyl-condensation reactions, 2, 539 Quinolizinones reactions, 2, 544 synthesis, 2, 567 Quinolizinones, nitro-synthesis, 2, 568 Quinolizin-4-ones nitration, 2, 529 synthesis, 2, 565 2,2 -Quinolyl... 

In this chapter the words labile and stable are used in a special context they derive their meaning from the original German papers and in fact refer to 9aH and 4/f-quinolizine derivatives respectively. 

The 9ai7-quinolizine structure (82) for the labile adduct from 3,5-dimethylpyridine was clearly established by the nuclear magnetic resonance studies of Richards and Higham, and subsequent work showed the labile adduct from 3-methylpyridine was analogous. As the labile adducts from all the pyridines and benzopyridines so far examined have very similar infrared absorption spectra in the 5-7 yn. (carbonyl and aromatic) region and within quite close limits very similar ultraviolet absorption spectra, it can be concluded that all are derivatives of 9aH-quinolizine,... 

Heating the 9-methyl-9aH-quinolizine (83) with 2-methylpyridine in methanol causes isomerization to the corresponding 9-methyl-4H-quinolizine (84), but with 3-methylpyridine the isomeric 7-methyl-4H-quinolizine (86) is obtained. Similarly the 9-methyl compound (83) and the corresponding 7,9-dimethyl derivative (82) with pyridine yield tetramethyl 47f-quinolizine-l,2,3,4-tetracarboxylate (78) with loss of the original alkylated pyridine. The mechanism of these reactions has not been established but the addition-elimination isomerization sequence for 3-methylpyridine accounts for the known cases of exchange of the pyridine (see Scheme 1). 

In methanol, isoquinoline and the ester gave the benzo[fif]indolizine [(121), cf. Section II,D,3] while in ether the labile adduct, tetra-methyl llbH-benzo[a]quinolizine-l,2,3,4-tetracarboxylate (122) was obtained. The labile adduct is much less easily isoraerized than the 9-methyl-9aH-quinolizines derived from pyridines (Section III,F,1) but with boiling xylene or, better, with sulfuric-acetic acids the cor-... 

A further application of the Dieckmann cyclization is that leading to the synthesis of 3,4,6,12-tetrahydro-l(2jE )-indolo[2,3-6]quinolizin-l-one (398). ... 

Chin-olizin, n. quinolizine. -olon, n. quino-lone. -omethan, n. quinomethan, quino-methane. 

Chemical Name 9-Fluoro-6,7-dihydro-5-methyl-1-oxo-1 H,5H-benzo[i,j] quinolizine-2-carboxylic acid... 

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