PROCESS FOR THE PREPARATION OF SPIRO-[cis

• Main Author: GONCZI, CSABA
• Format: Patent
• Language: English; Spanish
• Published: 20.08.2002
• Edition: 7

The invention relates to a process for the preparation of spiro[cis-4-(beta -hydroxyethyloxy) cyclohexane-[3H] -2' [1' H]-one derivatives of the formula (I) wherein R1 and R2 stand independently from each other for hydrogen, C1-4alkyl, C1-4alkoxy, C1-4alkylthio, C1-4polyfluroalkyl, C1-4polyfluroalkoxy, C3-7cycloalkyloxy, C3-7cycloakylthio, phenoxy, benzyloxy or nitro group by reduction of a dispiro [(1,3-dioxolane) -2, 4' -cyclohexane-1 ', 3"-[3H]indol] -2"[1"H]- one derivative of general formula (II), wherein R1 and R2 are as defined above, which comprises carrying out the reduction (a) with sodium cyanoborohydride in the presence of a Lewis acid, or (b) with sodium borohydride in the presence of a strong acid. La invencion se relaciona a un proceso para la preparacion de derivados espiro-[cis-4-(?- hidroxietiloxi)ciclohexano-[3H]-2'[1'H?-ona de la 5 formula (I) donde R1 y R2 estan colocados independientemente entre si por hidrogeno, grupo alquilo de C1-4, alcoxi de C1-4, alquiltio de C1-4, polifluoroalquilo de C1-4, poliflucroalcoxi de C1-4, cicloalquiloxi de C3-7, cicloalquiltio de C3-7, fenoxi, benciloxi o nitro mediante la reduccion de un derivado diespiro[(1,3-dioxolano)2,4'- ciclohexano-l',3''-[3H] indol]-2''?1''H] -ona de la formula general (II) en donde Rl y R2 son como se definio anteriormente," que comprende llevar a cabo la reduccion (a) con cianoborohidruro de sodio en la presencia de un acido de Lewis, o (b) con borohidrato de sodio en la presencia de un acido fuerte.