144522-58-7Relevant articles and documents
Aziridination of alkenes with 3-acetoxyaminoquinazolinones in the presence of hexamethyldisilazane
Atkinson, Robert S.,Barker, Emma,Ulukanli, Sabri
, p. 583 - 589 (2007/10/03)
Yields of aziridines from reaction of some alkenes, including α,β-unsaturated esters, with 3-acetoxyamino-2-isopropylquinazolinone 6 (Q3NHOAc) are greatly increased in the presence of hexamethyldisilazane (HMDS). A mono-aziridination product of naphthalene is obtained only in the presence of HMDS. It is concluded that the enhanced yields in these aziridinations are the result of scavenging of acetic acid by HMDS, thus prolonging the lifetime of the aziridinating agent Q3NHOAc.
Lithiation of 3-(acylamino)-2-unsubstituted-, 3-(acylamino)-2-ethyl-, and 3-(acylamino)-2-propyl-4(3H)-quinazolinones: Convenient syntheses of more complex quinazolinones
Smith,El-Hiti,Abdel-Megeed,Abdo
, p. 647 - 655 (2007/10/03)
3-(Pivaloylamino)- and 3-(acetylamino)-4(3H)-quinazolinones react with alkyllithium reagents to give 1,2-addition products in very good yields. Lithiation takes place with LDA and is regioselective at position 2. The lithium reagents thus obtained react with a variety of electrophiles to give the corresponding substituted derivatives in very good yields. Reactions of the lithium reagents with iodine give oxidatively dimerized cyclic structures. 3-(Pivaloylamino)- and 3-(acetylamino)-2-ethyl-4(3H)-quinazolinones and 3-(pivaloylamino)- and 3-(acetylamino)-2-propyl-4(3H)-quinazolinones are lithiated at the benzylic position with LDA. The lithium reagents so produced also react with a variety of electrophiles to give the corresponding 2-substituted-4(3H)-quinazolinone derivatives in very good yields. However, lithiation of 3-(acylamino)-2-(1-methylethyl)-4(3H)-quinazolinones was unsuccessful, as were lithiations of compounds having a diacetylamino group at position 3. The amide groups have been cleaved in good yield under basic or acidic conditions from some of the products to provide access to the free amino compounds.
Reaction of 3-(Acetoxyamino)quinazolin-4(3H)-ones with Enolic β-Diketones: the N-N Bond as a Chiral Axis in N-(3,4-dihydro-4-oxoquinazolin-3-yl)-N-acyl-α-aminoketones; Reductive and Base-catalysed Cleavage of the N-N Bond in N-Acetyl-N-(3,4-dihydro-4-oxoquinazolin-3-yl)-α-amino Aci...
Atkinson, Robert S.,Edwards, Paul J.,Thomson, Gordon A.
, p. 3209 - 3216 (2007/10/02)
Following the method of Foucaud and coworkers, reaction of pentane-2,4-dione with 3-(acetoxyamino)quinazolin-4-one 8 gave the keto amide 9 (15percent). 3-Methylpentane-2,4-dione reacts with compound 8 to give a relatively stable enol 11 (66percent) which can be isolated in a crystalline form.Rotation around the N-N bonds in both compounds 9 and 11 is believed to be slow on the real time-scale and hence the N-N bonds can be considered as a chiral axes.As a result, protonation of the enol double bond in compound 11 and the creation of an additional chiral centre, gives rise to the separable keto amides 14 and 15; this protonation can be accomplished completely diastereoselectively.Lead tetraacetate acetoxylation of compound 11 to give compound 11 to give compound 19 is also completely diastereoselective.Brief heating of the enol effects the elimination of the quinazolinone and the formation of the N-acetylimine 16 via an 8-membered transition state.Base-catalysed elimination of the quinazolinone ring from compound 22 is surprisingly easy: reductive cleavage of this N-N bond in compound 22 is facile by comparison with the 3-(alkylamino)quinazolin-4-ones.
