1898-07-3Relevant academic research and scientific papers
α-Alkylation of N-C Axially Chiral Quinazolinone Derivatives Bearing Various ortho -Substituted Phenyl Groups: Relation between Diastereoselectivity and the ortho -Substituent
Matsuoka, Mizuki,Iida, Asumi,Kitagawa, Osamu
supporting information, p. 2126 - 2130 (2018/06/08)
2-Ethylquinazolin-4-one derivatives bearing various ortho -substituted phenyl groups were revealed to possess a stable C-N axially chiral structure at ambient temperature. The reactions of alkyl halides with the anionic species prepared from these quinazolinones were systematically explored. The α-alkylation reactions proceeded with diastereoselectivities ranging from 1:1 to >50:1, depending upon the steric bulk of the ortho -substituent, to afford products having the elements of axial and central chirality in high yields (85-98%).
2-Ketoalkyl-4(3H)-quinazolinones
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, (2008/06/13)
2-Ketoalkyl-4(3H)-quinazolinones of the formula STR1 wherein R1 is an aliphatic, cycloaliphatic or hydrocarbon aromatic group of 1-10 carbon atoms; A is divalent alkylene of 1 to 10 carbon atoms; R2 is an aliphatic, cycloaliphatic, hydrocarbon aromatic or heterocyclic group of 1-10 carbon atoms formed by condensing an acyl ester of the formula R2 COOR' which can be dissociated to form --COR2 and R'OH in which R' is the alcoholic portion of said ester; and R3 and R4 are each hydrogen, hydroxy, amino, halogen, trifluoromethyl, alkyl, alkoxy, alkylthio or alkylsulfonyl each of 1-4 carbon atoms, the substituents other than hydrogen when present being preferably in the 6- and/or 7-position of the quinazolinone nucleus provide compounds having useful activity as CNS depressants and anticonvulsants. A process is provided for preparing such compounds by ester condensation of a corresponding 2-alkyl-3-substituted-4(3H) quinazolinone with a condensable ester and excess sodium hydride in the presence of a strong ionization solvent such as refluxing 1,2-dimethoxyethane.
Functionalization of 2-Methyl-3-o-tolyl-4(3H)-quinazolinone and Related Compounds through Carbanion Reactions at the 2-Methyl Group
Rathman, Terry L.,Sleevi, Mark C.,Krafft, Marie E.,Wolfe, James F.
, p. 2169 - 2176 (2007/10/02)
2-Methyl-3-o-tolyl-4(3H)-quinazolinone (methaqualone, 3a), 2,3-dimethyl-4(3H)-quinazolinone (3b), and 2-methyl-3-phenyl-4(3H)-quinazolinone (3c) were converted to the 2-lithiomethyl derivatives 4a, 4b, and 4c, respectively, by means of lithium diisopropylamide in THF-hexane at 0 deg C.Reactions of 4a-c with a series of electrophilic reagents led to elaboration at the original 2-methyl group.Thus, 4a was alkylated with methyl iodide, allyl bromide, and ethyl bromide, sulfenylated with diphenyl disulfide, and condensed with benzaldehyde and cyclohexanone.Although 4a failed to react with benzophenone and showed a preference for enolization with acetone and butanone, the less hindered salt 4b added readily to the carbonyl group of benzophenone and acetone.Lithio salt 4c underwent self-condensation on treatment with cyclohexanone.Photostimulated phenylation of 2-potassiomethyl derivative of 3a was effected with iodobenzene.Lateral acylation of 3a was accomplished with esters of aliphatic and aromatic acids in the presence of excess sodium hydride.
