US 7,547,791 B2
One-pot process for the preparation of antiemetic agent, 1,2,3,9-tetrahydro-9-methyl-3[(2-methyl)-1H-imidazole-1-yl)methyl]-4H-carbazol-4-O
Ashok Kumar, Maharashtra (India); Dharmendra Singh, Maharashtra (India); Atul Jadhav, Maharashtra (India); Navinchandra Darpan Pandya, Maharashtra (India); Shankar Deepak Panmand, Maharashtra (India); and Ramsingh Gajendrasingh Thakur, Maharashtra (India)
Assigned to IPCA Laboratories Ltd., Mumbai (India)
Appl. No. 11/666,330
PCT Filed Oct. 26, 2004, PCT No. PCT/IN2004/000336
§ 371(c)(1), (2), (4) Date Apr. 26, 2007,
PCT Pub. No. WO2006/046253, PCT Pub. Date May 04, 2006.
Prior Publication US 2008/0009635 A1, Jan. 10, 2008
Int. Cl. C07D 233/00 (2006.01)
U.S. Cl. 548—335.1  [548/300.1] 29 Claims
 
1. A one-pot process for preparing a compound of Formula-I

OG Complex Work Unit Drawing
comprising the steps of
a) reacting a compound of Formula IV

OG Complex Work Unit Drawing
with HNR1R2, or its salt, and paraformaldehyde in a solvent medium of acetic acid and hydrocarbon solvent to give a mixture of intermediate compounds of Formula III

OG Complex Work Unit Drawing
and Formula VIII

OG Complex Work Unit Drawing
wherein R1 and R2 are (i) independent alkyl groups, (ii) together forms a cyclic alkyl group, or (iii) together forms morpholine; and
b) reacting said mixture of intermediate compounds with 2-methyl imidazole in a solvent system to obtain the compound of Formula I in the same pot.