Ryan and Dunlka — Condensation of Aldehydes with fi-Diketones. 63 



Condensation of lenzaldehyde with mononiethtil-acetylawtone. 



A mixture of 10 grams of monomethyl-aeetylacetone and 37 grams of 

 benzaldehyde was saturated with gaseous hydrochloric acid under the same 

 conditions as in the previous experiment. The reaction, however, required 

 a longer time for its completion, and was, moreover, attended with the 

 formation of a considerable amount of tarry matter. The latter was 

 removed by repeated washing with cold alcohol until the residue was 

 nearly colourless. When recrystallised from chloroform and aicohol the 

 product was identical with the compound obtained, as described above, 

 from dimethyl-acetylacetone. On boiling with pyridine, hydrochloric acid 

 was split off and aV-diphenyl-/3-methyl-/3'-benzylidene-tetrahydro-y-pyrone 

 was obtained. 



Action of Hydroxylamine on the Tetrahydro-jjyrone Derivative. 



About 3'5 grams of sodium carbonate were added to a solution of 3 grams 

 of the tetrahydro-pyrone derivative, and 4 5 grams of hydroxylamine hydro- 

 chloride in alcohol, and the mixture was heated for three hours under a 

 reflux condenser. Water was then added, and the voluminous mass of 

 crystals was filtered. After drying, the hydroxylamine derivative was 

 recrystallised a few times from a large volume of chloroform. It formed 

 light felted needles, melting at 189-190° C. The yield was practically 

 quantitative. For analysis the crystals were dried at 140°, and gave the 

 following results : — 



0-2386 substance gave 0-6731 C0 2 and 01454 H 2 0, 

 0-2204 „ „ 0-6246 CO, „ 01312 H 2 0, 



0-2133 „ „ 0-6054 C0 2 „ 01302 H 2 0, 



0-3160 „ „ 10-3 e.c. N. at 750 rn.m.p. and 16° C. 



corresponding to C 77'3 H6 - 8, 



C77-3 H6-7, 

 C77-4 H6-8 N3-7, 

 C 25 H 23 2 . NHOH requires C 77'5 H 6-5 N 3-6. 



The crystals of the hydroxylamine derivative are insoluble in potash and 

 scarcely soluble in the ordinary organic solvents, 



