6.0 g of cinnamoyl chloride was dropwise added to a mixture of 8.7 g of pmethoxyphenylhydrazine hydrochloride, 10.1 g of triethylamine and 200 ml of
toluene under cooling at -5° to 0°C. The reaction mixture was stirred at 20°-
25°C for 1 h. The separated precipitates were filtered off and dry gaseous
hydrogen chloride was introduced into the filtrate. As a result a large amount
of crystals of N1-cinnamoyl-N1-(p-methoxyphenyl)hydrazine hydrochloride
were produced. These crystals were collected by filtration and washed with 20
ml of ether and dried to yield N1-cinnamoyl-N1-(p-methoxyphenyl)hydrazine
hydrochloride of melting point 183°-185°C.
A mixture of N1-cinnamoyl-N1-(p-methoxyphenyl)hydrazine hydrochloride and
acetonylmalonic acid was heated in acetic acid at heating with stirring.
Thereafter, the reaction mixture was allowed to cool, and was poured into cold
water, and then crystals were produced. They were collected by filtration, and
dried to give crude product. The recrystallization from acetone-water gave fine
white needle crystals of 1-cinnamoyl-2-methyl-5-methoxy-3-indolylacetic acid,
melting point 164°-165°C.
