( 43 ) 
l orthonitrostyrylaminoformate (see last communication). The b.p. is 
133°—135 at 5 mm. the 'melting point 22 3 — 23°. 
0,1450 gr. yielded 0,3081 gr. C0 2 and 0,0546 gr. H 2 0 
0,1591 gr. yielded 11,9 cc. N a at 756 mM. and 18° 
Found: 57,95% C; 4,18% H; 8,55% N. 
Calculated for C 8 H 7 N0 8 : 58*18% C ; 4,24% H; 848% N. 
The oxime crystallises from water in large white needles; m.p. 110°. 
0,1242 gr. yielded 0,2418 gr. C0 2 and 0,0507 gr. H,0 
0,0907 gr. yielded 11,9 cc. N s at 775 mM. and 16° 
Found : 53,10% C; 4,54°/ 0 H; 15,53% N. 
" Calculated for C 8 H 8 N s 0 8 : 53,33% C; 4,44% H; 15,55% N. 
The aldehyde is characterised by the strong reddening of the 
alkaline aqueous solution. It, further gives the ordinary reactions for 
aldehyde. 
. Reduced with iron powder in bisulphite solution it yields indole: 
kA 
A 
The idea of preparing the indole from orthonitrophenylacetaldehyde 
originated with A. von Baeyer *) ; he did not, however, realise his 
object, as his efforts to prepare the aldehyde ended in failure; up 
to the present this substance has not been prepared. 
The methyl m- and />nitrostyrylaminoformates give in an analogous 
manner the corresponding aldehydes. 
A method has thus been given to reduce the amides of the cin¬ 
namic acids to the aldehydes containing one carbon atom less. (I 
have not as yet tried the reaction with other aft unsaturated acids). 
Indole. 
For the practical preparation of the indole it is not necessary to 
prepare first the free aldehyde but the methyl orthonitrostyrylamino- 
formate is reduced in alcoholic solution with dilute acetic acid and 
iron powder, and the whole is then made strongly alkaline. This 
causes the urethane to saponify and the vinyl alcohol formed then 
condenses at once to indole which is then distilled in steam. The 
distillate is so charged with indole that this crystallises in the receiver. 
This indole is quite white and pure; m.p. 52°. 
0 Lecture by A. v. Baeyer Ber. 33, Sonderheft biz. LV1II, 
