ORGANIC SPECTROSCOPY INTERNATIONAL: OLANZEPINE KEY INT........N-desmethyl olanzapine

N-desmethyl olanzapine

http://www.google.com.tr/patents/US20050272720

EXAMPLE 5 N-Methylation of N-desmethyl olanzapine and isolation of olanzapine as the acetate salt

Reaction scheme:

In a 250 ml flask, equipped with a magnetic stirrer 3.0 g of N-desmethyl olanzapine was dissolved in 30 ml of DMSO. Then, 0.852 g of 37% formaldehyde and 0.492 g of formic acid were added and the resulting mixture was heated at 80° C. for 2 hours. After cooling to room temperature, 120 ml of ethyl acetate and 120 ml of water were added. The organic layer was washed twice with 100 ml water and once with 100 ml saturated aqueous NaCl, dried over Na₂SO₄, and concentrated at reduced pressure to a volume of about 25 ml. Then, 1.0 ml acetic acid was added, and the resulting mixture was stirred for 3 days at 4° C. The product (light yellow) was isolated by filtration, and washed with 5 ml of diethyl ether, and dried subsequently at ambient conditions. Isolated yield: 1.19 g (58%) (=. batch.01).

Then, drying of 0.40 g of batch.01 in vacuum at 70° C. for 2 days yielded olanzapine free base quantitatively. Data: ¹H-NMR and XRPD confirm Olanzapine Form I.