Synthesis and reactions of 10,10‐dimethyl‐10 H ‐pyrido[1,2‐ a ]indol‐6‐ones

Cyclocondensation of 2,3,3‐trimefhyl‐3 H ‐indoles 2 with malonates 3 gives 8‐hydroxy‐10,10‐dimefhyl‐10 H ‐pyrido[1,2‐ a ]indol‐6‐ones 4 , which were halogenated in position 7, 8 and 9 with sulfuryl chloride, bromine or phosphoroxychloride to give the corresponding halo‐10,10‐dimethyl‐10 H ‐pyrido[1,2‐ a ]indoles 5, 6, 7 and 8 . Amination affords the 8‐amino‐10,10‐dimethyl‐10 H ‐pyrido[1,2‐ a ]indol‐6‐one 9 . Nitration gives either the 10,10‐dimethyl‐7‐nitro‐10 H ‐pyrido[1,2‐ a ]indoles 10 or 10,10‐dimethyl‐7‐hydroxy‐10 H ‐pyrido[1,2‐ a ]indoles 11 , depending on the conditions.