1490067 2-Phenyl-benzoxazoles LILLY INDUSTRIES Ltd 22 Oct 1974 [23 Oct 1973] 49258/73 Heading C2C Novel 2-phenyl-benzoxazoles of the general formula wherein the -CRSP1/SPRSP2/SPRSP3/SP group is in the 5- or 6- position of the benzoxazole nucleus, RSP4/SP is a phenyl group optionally substituted by at least one C 1-6 alkylsulphonyl, halogen, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 haloalkyl, nitro, C 2-7 acyl, hydroxy, amino, C 1-6 alkylamino or C 2-7 acylamino radical or optionally substituted in two adjacent positions by a methylene- or ethylene-dioxy radical, RSP3/SP is a nitrile group, a carboxy group or a salt, ester, amide or hydroxamic acid derivative thereof, or a hydroxymethyl group or an ester thereof, RSP1/SP is a hydrogen atom or a C 1-6 alkyl group and RSP2/SP is a halogen atom or a hydroxy or C 2-7 acyloxy group, are prepared by cyclizing a benzene derivative of the general formula wherein V, W and Z are respectively RSP1/SP, RSP2/SP and RSP3/SP or atoms or groups which are respectively convertible to RSP1/SP, RSP2/SP and RSP3/SP and either X is a hydrogen atom or RSP4/SPCO- and Y is H 2 N- or X is a hydrogen atom and Y is RSP4/SPCONH- or RSP4/SPCH=N-, the cyclization being effected, in the case where X is a hydrogen atom and Y is H 2 N-, in the presence of RSP4/SPCOOH, (RSP4/SPCO) 2 O, RSP4/SPCOOl, RSP4/SPCONH 2 , RSP4/SPCONHNH 2 , RSP4/SPCN, or RSP4/SPCCl=NRSP7/SP (RSP7/SP is C 1-4 alkyl) and thereafter, where one or more of V, W and Z in the product are not the same as RSP1/SP, RSP2/SP and RSP3/SP, respectively, converting V, W and/or Z to RSP1/SP, RSP2/SP and/or RSP3/SP in conventional manner. 2 - p - Chlorophenyl - 6 - benzoxazolylcarboxaldehyde is prepared by brominating 2-pchlorophenyl - 6 - methyl - benzoxazole and oxidizing the resulting 2 - p - chlorophenyl - 6- benzoxazolylmethyl bromide. The novel 2-phenyl-benzoxazoles can be reduced to give the corresponding compounds in which RSP2/SP is a hydrogen atom.
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