| 摘要 |
<p>A process for the preparation of a compound of formula (I) wherein R?1, R2, R3 and R4¿ are each independently hydrogen, optionally substituted alkyl, optionally substituted alkenyl, alkynyl, cycloalkyl, alkylcycloalkyl, optionally substituted aryl, optionally substituted arylalkyl, optionally substituted aryloxy, optionally substituted arylalkoxy, alkoxy, alkenyloxy, alkynyloxy, hydroxyalkyl, alkoxyalkyl, alkylthio, alkenylthio, alkynylthio, haloalkyl, haloalkenyl, haloalkynyl, haloalkoxy, haloalkenyloxy, haloalkynyloxy, haloalkylthio, haloalkenylthio, haloalkynylthio, halogen, hydroxy, cyano, nitro, -NR?5R6, -NR7COR8, -NR7CSR8, -NR9SO¿2R10, -N(SO¿2-R?11), -(SO¿2?-R?12), -COR13, -CONR14R15, -COOR16, -OCOR17¿, -OSO¿2?R?18, -SO¿2NR?19R20, -SO¿2R?21, -SOR22, -CSNR23R24, -SiR25R26R27¿, -OCH¿2CO2R?28, -OCH¿2?CH2CO2R?29, -SO¿2Z, -CONR30SO2R31, -NHCONR32R33, -NHCSNR32R33, or an adjacent pair of R?1, R2, R3 and R4¿ when taken together form a fused 5- or 6-membered carbocyclic or heterocyclic ring; R?5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32 and R33¿ are each independently selected from hydrogen, alkyl, alkenyl, alkynyl, haloalkyl, haloalkenyl, haloalkynyl, optionally substituted aryl and optionally substituted arylalkyl; Z is halogen; and X is oxygen or sulphur, which comprises (a) reacting a substituted ortho-nitro or -nitroso phenol or a substituted ortho-nitro or -nitroso thiophenol of formula (II), wherein R1-R4 and X have the values previously defined, and y is 1 or 2, with a reducing agent comprising an alkali metal dithionite in an alkaline reaction medium in the presence of carbon disulphide, to form the substituted 2-mercaptobenz-oxazole or -thiazole of formula (III) wherein R1-R4 and X have the values previously defined, acidifying the reaction mixture and collecting the 2-mercaptobenz-oxazole or -thiazole; and (b) reacting the 2-mercaptobenz-oxazole or -thiazole (III), with a compound of formula (IV) CF¿2?=CH-CH2-CH2-L wherein L is a good leaving group to form the compound of formula (I).</p> |
