GB1084175A - - Google Patents

Abstract

1,084,175. Oxazolyl-thiophene compounds. CIBA Ltd. March 9, 1965 [March 20, 1964], No. 9994/65. Heading C2C. [Also in Divisions C3, C5 and D1] The invention comprises oxazolyl-thiophene compounds of the formula where one of X and X 1 is hydrogen and the other a nitrogen containing group which is a primary, secondary or tertiary amino group, a carboxylic acylamino group, a sulphonamido group, a urea group or a heterocyclic ring containing nitrogen as a hetero atom, the nitrogen-containing group being bound to the benzene ring through a trivalent nitrogen atom. The preferred compounds are those in which X is hydrogen and X 1 is -NH-alk, where alk is optionally substituted alkyl, -NH-CO-Ac and -NH-SO 2 -Z and -NH-CO-NH-Z, where Ac and Z are optionally substituted aliphatic or aromatic residues, -NH-Q, where Q is a 4,6-disubstituted-s-triazin-2-yl radical, or the radical (10) where T is the residue of a benzene, naphthalene or acenaphthene ring, or the radicals (11) or (12) where M 1-4 are hydrogen, C 1-4 alkyl or phenyl groups. The compounds are made by reducing the nitro group of a compound where one of X 2 and X 3 is hydrogen and the other nitro, to the corresponding amine and, if desired, converting this amino group to various values of X or X 1 by known methods, e.g. by alkylation, or reaction with a carboxylic acid chloride, sulphonyl chloride or isocyanate. The compounds in which X 1 is the radical (10) are made by diazotization of the corresponding amine followed by coupling with a primary amine of the benzene, naphthalene or acenaphthene series. The compounds in which X 1 is the radical ( 11 ) are prepared by converting the amino group to a hydrazino group followed by condensation with the appropriate α,γ-dicarbonyl compound or 3-ketoacetal. The compounds in which X 1 is the radical (12) are made by converting the amino group to an azido group followed by reaction with the appropriate acetylene compound. The nitrocompounds used as starting materials can be made by reacting a monocarboxylic acid of the formula or a functional derivative thereof, with a amino phenol of the formula wherein one of X 2 or X 3 in (15) or (16) is H and the other is a nitro group, preferable at an elevated temperature in the presence of a catalyst. The novel compounds are used as optical brightening agents (see Divisions C3, C5, D1). Numerous examples are provided.