The Synthesis of Potential Antimalarials. 7-Chloro-α-(2-piperidyl)-4-quinolinemethanol¹

Cyclization of Cyanoethylated Ketones as a Route to 6‐Substituted Indole Derivatives

“…Acidification of the mother liquor with hydrochloric acid after isolation of the 4‐isomer, 36 , gave, due to cyclization of 37 , the 6‐isomer in pure form. The relative ratio of the isomers was 2:1 with the 4‐chloroisomer predominating, which is in agreement with results reported by Senear but in disagreement with the relative yields reported by Sadler, who reported the ratio 33/35 with the 6‐isomer slightly predominating . The facile synthesis of 33 and 36 is in sharp contrast to a report by Kraynack et al .…”

“…4‐Chloroisatin 36 gave the following data, mp 257–258°C (lit. mp 256.5–258°C). IR 3280, 1731, 1608, 1439, 1245, 1160, 915 cm −1 .…”

“…The mother liquor from the preparation earlier was acidified with hydrochloric acid, and the orange solid formed was collected after 1 h, 7.7 g (22%), mp 258–259°C (lit. mp 258–259°C). IR 3180, 1742, 1715, 1609, 1443, 1326, 1207, 1098, 1064, 953, 920, 892 cm −1 .…”

An Antimalarial Alkaloid From Hydrangea. Xiv. Synthesis of 5-, 6-, 7-, and 8-Monosubstituted Derivatives

“…°Prepared by 48% hydrobromic acid hydrolysis of the compounds in Table III as described for the dZ-alkaloid (3). 6 Methoxyl analysis showed one methoxyl still present. 6-Methoxy-4-quinazolone is recovered unchanged by these hydrolysis conditions.…”

“…The product was collected and washed with water; yield, 7.9 g. (86%), m.p. " These compounds were prepared by 6 N hydrochloric acid hydrolysis of the compounds of Table II Similarly, 6-carbomethoxy-4-quinazolone was obtained in 80% yield, m.p. 208-210°from the corresponding acid (22) except it was necessary to acidify the ammonia solution to pH 8 for crystallization of the product.…”