HAVEMEYERLABORATORIES UKIVERSITY, No. 26.1
[COXTRIBUTIONS FROM THE
OF
COLCMBI.4
T H E DIRECT SYNTHESIS OF KETODIHYDROQUINAZOLlNS FROM ORTHOAMINO ACIDS.' BY
MARSTOX
TAYLOR BOGERTA N D
AUGCST
HENRY
GOrTHELF
Received lime 18, IQW
A
S announced in our preliminary paper on this subject,' ketodihydroquinazolins (or oxyquinazolins) can readily be obtained by the action of nitriles upon orthoamino acids under conditions of heat and pressure. T h e present paper is confined to a discussion of the 2-inethyl-4-ketodihydroquinazolin. Many others have been prepared and studied, and will form the subjects of later communications. For convenience, throughout this article we have called o u r compound a quinazolon" although we do not intend thereby to indicate any preference for the keto form as compared with the tautomeric oxyquinazolin form. T h e numbering for t h e quinazolin nucleus is that first suggested by Paal and Busch.$ 8
I
7
I
N
6
/ '
3
/
5 4 Weddige* the discoverer of this 2-inethyl-4-ketodihydroquinazolin, obtained it from orthoacetaniinobenzamide by fusion, by solution in alkalies with subsequent precipitation with acid, o r by long boiling with water ; also, by heating ethylorthoacetaminobenzoate to 160" C. with strong aqueous ammonia. Bischler and Burkart' accomplished the same result by fusing the ammonium salt of orthoacetaminobenzoic acid, while NiementowskT prepared it by heating together anthranilic acid and acetamide. 1 Read before t h e joint meeting of the American Chemical Society and Section C of t h e American Association for t h e Advancement of s c i e n c e , June 25, rpo. 2 T h i s Journal, 02, 129. 8 Bey. d . chem. Ges., aa, 2684. 4 J . p r a k t . Chem. [ z ] , 31, 124; 36, 143. 3 Ber. d . chem. Ges., 16. 1350. 6-T. prakl. Chcm. [ 2 ] , 51,
sa.
523
KETODIHYDROQUINAZOLINS.
T h e syntheses of Weddige and Bischler are practically identical, both depending upon the formation of orthoacetaminobenzamide, from which the quinazolon results by loss of water. T h e course. of Niementowski's synthesis is probably similar in the main, the following reactions being suggested in explanation :
1:::+-
A
( \
cH3.co.NH,=
C6H4
