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acid to ketodihydroquinazolines (quinazolones). Quinazoline (C6H2N,) is obtained by oxidizing its dihydro-derivative with potassium ferricyanide. The dihydro derivatives exist in three different See also:

SERIES (a Latin word from serere, to join)

series, since the addition of two atoms of See also:

HYDROGEN [symbol H, atomic weight x-oo8 (0=16)]

hydrogen in the diazine See also:

RING (O.E. hring; a word common to Teutonic languages; and probably cognate with the Lat. circus, Gr. KtpKOS or KpLKOS, Skt'. chakra, wheel, circle, cf. also " harangue "); in art, a band of circular shape of varying sizes, made of any material and used f

ring can take See also:

PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place in three different positions, namely, in the 3.4, 1.4 and 1.2 positions, and these different types are distinguished by the symbols Al, See also:

A2(z)

A2, A3, denoting that the double linkage is between the first and second, second and third, and third and See also:

FOURTH

fourth atoms in the diazine ring. The Al series, which are obtained by the elimination of the elements of See also:

WATER

water from the acidyl derivatives of ortho-aminobenzylamines, are rather strong bases which form stable salts and yield the corresponding keto derivatives on oxidation (C. Paal, Ber., 1889-1896). 4-Keto-dihydroquinazoline (/3-quinazolone) is formed by oxidizing the dihydro See also:

BASE

base with potassium permanganate; by boiling acidyl-ortho-aminobenzamide with water (A.

Weddige, Jour. prak. Chem., 1885, (2) 31, p. 124) ; or by See also:

HEATING

heating See also:

ant hranilic acid with formamide (S. Niementowski, Ber., 1895, 28, p. 443). It reacts both in the enol and keto forms, yielding both N-See also:

ETHERS

ethers and 0-ethers, the latter being obtained by the See also:

ACTION

action of sodium alcoholates on 4-chlorquinazolines. The A2 series is obtained by heating acidyl-ortho.. aminobeuzylamines with See also:

ZINC

zinc chloride, whilst the A3 series, which !!~ N (1) holic See also:

AMMONIA (NH3)

ammonia on the acidyl derivatives of orthowith the cinnolines, See also:

PHTHALAZINES (benzo-orthodiazines or benzopyridazines)

phthalazines and quinoxa-(2) lines. They maybe obtained by the action of alco- is only known in the form of its keto derivatives (a-quinazolines), results from the fusion of See also:

UREA, or CARBAMIDE, CO(NH2)2

urea with ortho-aminobenzaldehydes and benzophenones, the elements of water and of ammonia being eliminated (S. See also:

GABRIEL (Heb. SKns, man of God)

Gabriel and Th. Posner, Ber., 1895, 28, p. 1037). They possess feeble basic and phenolic characters.

The tetra-hydroquinazolines are obtained by reducing the quinazolines and dihydroquinazolines and by condensing ortho-aminobenzylamine with See also:

ALDEHYDES

aldehydes (M. See also:

Busch, Jour. prak. Chem., 1896, (2) 53, p. 414). The ring is easily split on See also:

HYDROLYSIS (Gr. 6Swp, water, Anew, to loosen)

hydrolysis, giving rise to ortho-disubstituted benzenes. The keto derivatives of this series result by the action of carbonyl chloride on ortho-aminobenzylamines of the type H_N.See also:

C6H,.CH,NHR (M. Busch, Ber., 1892, 25, p. 2853), or from the urea derivatives of ortho-aminobenzylamine. They are weak bases which are indifferent to both acids and alkalis, and which on oxidation yield the corresponding 2.4-diketo derivatives.

End of Article: QUINAZOLINES (Phenmiazines or benzopyrimidines)

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