286 CAROTENOID CARBOXYLIC ACIDS XIII 



KuHN and Brockmann^^^ converted azafrinone into the acid chloride by 

 means of thionyl chloride and allowed the acid chloride to stand in benzene 

 solution with ammonia. The reaction product was purified by chromatography 

 on a calcium carbonate column from benzene solution. The amide crystallises 

 from methanol in red needles, m.p. 177-178°. It is sparingly soluble in hexane, 

 petroleum ether and petrol, but readily soluble in chloroform, carbon disulphide 

 and hot benzene or methanol. 



Anhydroazafrinone C27H34O3: 

 CHo CHo 



\V 



/\ I r I 



CH2 C-CH=CH-C=CHCH=CH-C=CHCH=CHCH=C-CH=CH-COOH 

 CH2 — C-CO-CHa Anhydroazafrinone 



Anhydroazafrinone is obtained by the action of potassium hydroxide on 

 azafrinone^^^. It crystallises from dilute methanol in dark red prisms, m.p. 196°. 

 The solubility in hexane, petroleum ether and petrol is very small; it is some- 

 what better in chloroform, carbon disulphide, hot benzene or hot methanol. 



Solvent Absorption maxima 



Carbon disulphide 511 476 447 m^ 



Hexane 478 449 420 m/i 



Benzene 493 460 430 m// 



Petroleum ether 477 447 419 m/i 



Chloroform 493 459 433 m/z 



Ethanol (479) (449) m/< (diffuse) 



Anhydroazafrinone ni'thyl ester C28H3g03^'' : 



This ester is prepared by the esterification of anhydroazafrinone with diazo- 

 methane. It separates from dilute methanol in crystals, m.p. 153°. 



Solvent Absorption maxima 



Petrol 479 448 420 m// 



Anhydroazafrinone oxime methyl ester C^^Yi^^O^'^^'' : 

 CHo CHo 



\V 



C CHo CH3 CH« 



/\ I I I 



CH» C- CH=CH- C=CHCH=CH- C=CHCH=CHCH=C- CH=CH- COOCH, 



r II 



CHa— C-C(CH3)=N0H 



Anhydroazafrinone oxime methyl ester is obtained by treating anhydro- 

 azafrinone methyl ester with excess hydroxylamine and a little alkali. For 

 References p. 2go-2g4. 



