The invention concerns alpha crystalline form of the compound of formula (I), characterised by its X-ray diffraction pattern on powder. The invention is useful for preparing medicines. 0 12, PLACE DE 1A DEFENSE, F-92415 COURBEVOIE CEDEX, FRANCE, LES LABORATOIRES SERVIER IN/PCT/2002/01815/MUM A (PCT/FR01/02167) IN/PCT/2002/01815/MUM A (PCT/FR01/02167) INDIA 2009-03-25T18:02:56Z 2005-02-04 2002-12-16 412641 C07D 209/42 1) PFEIFFER BRUNO 2) GINOT YVES-MICHEL 3) COQUEREL GERARD 4) BEILLES STEPHANE -2 0 1075 FRANCE 2000-07-06 00/08793 2005-02-04 0 21WrGv0i 2009-04-30T18:55:08Z 129152 1) PFEIFFER BRUNO 2) GINOT YVES-MICHEL 3) COQUEREL GERARD 4) BEILLES STEPHANE 1327 LES LABORATOIRES SERVIER