Reference

A process for the preparation of cilostazol and the intermediates thereof

A process for the preparation of cilostazol and the intermediates thereof. Beltrame, Andrea; Castaldi, Graziano (Dipharma S.P.A., Italy). PCT Int. Appl. WO 2005019204 A1 3 Mar 2005, 12 pp. DESIGNATED STATES: W: AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BW, BY, BZ, CA, CH, CN, CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NA, NI, NO, NZ, OM, PG, PH, PL, PT, RO, RU, SC, SD, SE, SG, SK, SL, SY, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, YU, ZA, ZM, ZW; RW: AT, BE, BF, BJ, CF, CG, CH, CI, CM, CY, DE, DK, ES, FI, FR, GA, GB, GR, IE, IT, LU, MC, ML, MR, NE, NL, PT, SE, SN, TD, TG, TR. (English). (World Intellectual Property Organization). CODEN: PIXXD2. CLASS: ICM: C07D401-12. ICS: C07D257-04. APPLICATION: WO 2004-EP8475 29 Jul 2004. PRIORITY: IT 2003-MI1670 26 Aug 2003. DOCUMENT TYPE: Patent CA Section: 28 (Heterocyclic Compounds (More Than One Hetero Atom)) There is provided a process for the prepn. of 5-(4-halobutyl)-1-cyclohexyl-1H-tetrazole compds. 73963-42-5 which is the cas registry number is also used here. of formula (I) (X = halo) which process comprises reacting N-cyclohexyl-5-halopentanamide of formula (II) (X = same as above) with phosphorus pentachloride (PCl5) and reacting the resulting a haloimine (e.g. N-cyclohexyl-5-chloropentanimidoyl chloride) of formula X(CH2)4C(Cl):N-cyclohexyl with trimethylsilyl azide. Cilostazol (III) is prepd. 73963-42-5 which is the cas registry number of one of substances is just one of reagents here. by reacting the compds. I with 6-hydroxy-1,2,3,4-tetrahydroquinolin-2-one. Thus, 15.9 g phosphorus pentachloride and 12.8 g N-cyclohexyl-5-chloropentanamide are mixed in 120 g toluene at room temp. The mixt. is left under stirring for about 3 h, then 9.8 g trimethylsilyl azide was added. The reaction mixt. was kept at room temp. for about 16 h and treated with 50 g water to give, after workup, 13.3 g 1-cyclohexyl-5-(4-chlorobutyl)tetrazole (~93% yield). ..

A process for the preparation of cilostazol and the intermediates thereof

A process for the preparation of cilostazol and the intermediates thereof. Beltrame, Andrea; Castaldi, Graziano (Dipharma S.P.A., Italy). PCT Int. Appl. WO 2005019204 A1 3 Mar 2005, 12 pp. DESIGNATED STATES: W: AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BW, BY, BZ, CA, CH, CN, CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NA, NI, NO, NZ, OM, PG, PH, PL, PT, RO, RU, SC, SD, SE, SG, SK, SL, SY, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, YU, ZA, ZM, ZW; RW: AT, BE, BF, BJ, CF, CG, CH, CI, CM, CY, DE, DK, ES, FI, FR, GA, GB, GR, IE, IT, LU, MC, ML, MR, NE, NL, PT, SE, SN, TD, TG, TR. (English). (World Intellectual Property Organization). CODEN: PIXXD2. CLASS: ICM: C07D401-12. ICS: C07D257-04. APPLICATION: WO 2004-EP8475 29 Jul 2004. PRIORITY: IT 2003-MI1670 26 Aug 2003. DOCUMENT TYPE: Patent CA Section: 28 (Heterocyclic Compounds (More Than One Hetero Atom)) There is provided a process for the prepn. of 5-(4-halobutyl)-1-cyclohexyl-1H-tetrazole compds. 73963-42-5 which is the cas registry number is also used here. of formula (I) (X = halo) which process comprises reacting N-cyclohexyl-5-halopentanamide of formula (II) (X = same as above) with phosphorus pentachloride (PCl5) and reacting the resulting a haloimine (e.g. N-cyclohexyl-5-chloropentanimidoyl chloride) of formula X(CH2)4C(Cl):N-cyclohexyl with trimethylsilyl azide. Cilostazol (III) is prepd. 73963-42-5 which is the cas registry number of one of substances is just one of reagents here. by reacting the compds. I with 6-hydroxy-1,2,3,4-tetrahydroquinolin-2-one. Thus, 15.9 g phosphorus pentachloride and 12.8 g N-cyclohexyl-5-chloropentanamide are mixed in 120 g toluene at room temp. The mixt. is left under stirring for about 3 h, then 9.8 g trimethylsilyl azide was added. The reaction mixt. was kept at room temp. for about 16 h and treated with 50 g water to give, after workup, 13.3 g 1-cyclohexyl-5-(4-chlorobutyl)tetrazole (~93% yield). ..