Crystalline Forms of Isobutyric acid 2-(3-(diisopropylamino)-1(R)-phenylpropyl)-4- (hydroxymethyl)phenyl ester hydrogen base (17-Nov-2009)

Crystalline Forms of Isobutyric acid 2-(3-(diisopropylamino)-1(R)-phenylpropyl)-4-

(hydroxymethyl)phenyl ester hydrogen base

    Isobutyric acid 2-(3-(diisopropylamino)-1(R)-phenylpropyl)-4- (hydroxymethyl)phenyl ester hydrogen base ("FSB") of the following structure

is an intermediate in the synthesis of isobutyric acid 2-(3-(diisopropylamino)-1(R)- phenylpropyl)-4- (hydroxymethyl)phenyl ester hydrogen fumarate ("FSF").

FSF is a selective M3 antimuscarinic agent indicated for the treatment of overactive bladder syndrome with symptoms of urgency, urinary incontinence and increased urinary frequency. FSF is marketed under the trade name Toviaz® by Pfizer.

A new crystalline form of FSB was found and is described herein below.

Crystalline FSB

    The crystalline form of FSB is characterized by data selected from a group consisting of: an X-ray powder diffraction having peaks at about 8.8, 10.8, 19.0, 22.5 and
25.0 ± 0.2 degrees two-theta; an XRPD pattern as depicted in Figure 1, and combinations thereof.

Figure 1. X-ray powder diffraction (XRPD) pattern of FSB.

    The above crystalline FSB can be further characterized by data selected from a group consisting of: an X-ray powder diffraction pattern having peaks at about 13.7, 15.6,
16.8, 20.3, 21.7 and 23.5 ± 0.2 degrees two-theta; a FT-IR spectrum having peaks at about 3595, 2983, 2713, 1741, 1496, 1469, 1387, 1354, 1213, 1177, 1137, 1034, 871, 820 and 700 cm^-1 ± 4 cm^-1; a FT-IR spectrum as depicted in Figure 2, and combinations thereof.

Figure 2. FT-IR spectrum of crystalline FSB.

2

EXAMPLES

    The X-ray powder diffraction pattern was measured with ARL X-ray powder diffractometer model X`TRA-030, equipped with Cu irradiation source =1.54178 Ǻ, Peltier detector, and with a round standard aluminum sample holder with round zero background quartz plate. Scanning p...