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The title compounds, e.g. 3, are highly selective acetylating agents for primary amines in the presence of secondary amines and, in particular, for the less sterically hindered of two different secondary amines.

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Two diastereoisomers of 3-(diacylamino)quinazolinone 5 are separated and identified by crystal structure determinations which confirm the presence of an N-N chiral axis: one diastereoisomer of enantiopure 8 reacts with racemic 1 -phenylethylamine exclusively at the 2-acetoxypropanoyl imide carbonyl group and with kinetic resolution to give a 3.6 : 1 ratio of diastereoisomers of 10.The barriers to rotation around N-N bonds in di-, tri-, and tetra-acyl-substituted hydrazines are large by comparison with those around most other single bonds.' Verma et aZ.2 have shown that the barrier to rotation around the N-N bond in N,N-diacetylaminocamphorimide 1 is in excess of 97 kJ mol-l since no coalescence of the signals from the acetyl methyl groups was observed in its NMR spectrum at 150 "C.We have prepared a number of 3-( diacy1amino)quinazolinones 2 from the corresponding 3-aminoquinazolinones 3 (Scheme 1). The monoacylation products 4 are isolated in good yields begause diacylation is a much slower reaction under the same conditions: this allows reaction to be carried out with a second acyl group that is different from the first.Using the method in Scheme 1, the compound 5 has been prepared by reaction of 2-phenylpropanoyl chloride with the appropriate 3-(acetylamino)quinazolinone as a mixture of diastereoisomers 5a and 5b (1.8: 1). Separation of these 0 COMe 1

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

No abstract

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Pyridinium imides 3-5 and 8 are obtained as crystalline solids from the reaction of 3-acetoxyaminoquinazolinones 2 and 10 with the corresponding pyridines; barriers to rotation around each of the N-N bonds in 3 have been measured by NMR spectroscopy, and the imides 3-5 react both with styrene and with diethyl fumarate to give the corresponding aziridines.