Dibenz oxazepines

Chamicel Name 2-Chloro-11-(1-piperazinyl)dibenz[b,f] [1,4] oxazepine... 

A mixture of 10 g of the above piperazine carboxylate ester, 8 g of phosphorus pentoxide and 20 ml of phosphorus oxychloride is heated under reflux for about 1 day, diluted with 100 ml each of chloroform and benzene and quenched with 200 g of ice. The mixture is made basic with 10% sodium hydroxide. Theorganic layer is Isolated and extracted with 150 ml of dilute hydrochloric acid. The product is precipitated from the aqueous layer by addition of 10% sodium hydroxide, extracted with benzene and dried over potassium carbonate. Recrystallization from benzene-petroleum ether gives 2[Pg.77]

This crude product is dissolved in 100 ml of dilute hydrochloric acid, the acid solution is extracted with ether, and the aqueous layer is made basic with sodium hydroxide solution (3N) in the presence of ether (approximately 250 ml). The ether layer Is separated, dried over potassium hydroxide and evaporated to a white solid. Additional purification by repeating the formation of the hydrochloric acid salt and reprecipitation of the base is carried out. When purified in this manner, followed by drying at 80°C in vacuo over phosphorus pentoxide, 2-chloro-11-(4-methyl-1-piperazinyl)dibenz[b,f] [1,4]oxazepine, li/IP 109° to 111°C, is obtained. 

The first reported derivative of 1,2-oxazepine was dibenz[f,/][l,2]oxazepine-ll-carbonitrile (3 a). This, together with small amounts of compounds 4 and 5, is formed when acridine-9-carbonitrile 10-oxide (la) is irradiated with UV light,6,7 It is likely that the reaction proceeds by way of the oxaziridine valence tautomer 2a, which, however, was not detected.7 Photo-isomcrization of 9-chloroacridine 10-oxide (lb) yields the 11-chlorodibenzoxazepine 3b.6,7... 

Dibenz[(j,/][1,4]oxazepines 2 are readily obtained by the cyclodehydration of 2-(acylamino)-phenyl phenyl ethers 1 in polyphosphoric acid.38... 

Dibenz[6,/][l,4]oxazepin-ll(10//)-ones 4 are formed in near quantitative yield by cycli-zation of aryl 2-isocyanatophenyl ethers 3 in the presence of aluminum trichloride. Exact yields were not reported.40... 

The cyclization of imines 7, induced by the isopropyloxycarbonyloxy radical (i-PrOC02). obtained by homolytic cleavage of diisopropyl peroxydicarbonate, leads to dibenz[6,/][l,4]-oxazepines 8, accompanied by traces of biphenyls and benzoxazoles.424... 

Dibenz[6,/][l,4]oxazepines are reduced to the 10,11-dihydro compounds 1 by catalytic hydrogenation in the presence of palladium on charcoal and a trace of Raney nickel.44... 

Ballantyne, B. The acute mammalian toxicology of dibenz(b,f)-l,4-oxazepine. Toxicology 8 347-379, 1977. 

The effect of the riot control agent dibenz(b,f)-1,4-oxazepine (CR) in the rabbit eye. Toxicol. Appl. Pharmacol. 34 45-48, 1975. 

The unstable dibenz[c,/][l,2]oxazepines (312 R = CN, Cl) have been isolated as the major products of the UV irradiation of 9-cyano- and 9-chloro-acridine 10-oxides (310) in benzene (c/. the analogous Af-imide to 1,2-diazepine conversion on p. 598). Although none of the oxaziridine tautomer (311) was detectable by UV spectroscopy, the subsequent deoxygenation of (312) to acridine suggests the existence of a thermal equilibrium between (311) and (312) (79T1273). These dibenzo compounds (312) are the only fully unsaturated oxazepines yet isolated but the 2,3-benzoxazepin-l-one system (314) has recently been prepared by the reaction of benzonitrile oxide with the benzopyranone (313) (80JCS(Pl)846). 

Dibenz[6,/][ 1,4]oxazepines, which have intense lachrymatory and skin irritant properties, can be prepared in high yield by the Bischler-Napieralsky-type cyclization of N- 2-phenoxyphenyl)formamides (76JCS(P1)1279>. 

Unstable dibenz[c,/ [l,2]oxazepines (73 R = CN, Cl) are major products of the UV irradiation of 9-cyano- and 9-chloro-acridine 10-oxides (71) in benzene. No oxaziridine tautomer (72) was detectable by UV spectroscopy. 

Chemical Name 2-Chloro-ll-(l-piperazinyl)dibenz[b,f][l,4]oxazepine Common Name -Structural Formula ... 

---