摘要:
Disclosed is a process for the preparation of 5-alkoxy-2-nitrosophenols by the nitrosation of 3-alkoxyphenols using an alkali metal nitrite and an alkanoic acid wherein the selectivity of the nitrosation is improved. Also disclosed is a 2-step process for the preparation of 5-alkoxy-2-nitrophenols by oxidizing the 5-alkoxy-2-nitrosophenols obtained in accordance with the present invention.
摘要:
Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a releasable 6-(2-thienylazo)-3-pyridinol cyan dye moiety or precursor thereof, the compound containing:(a) in the 3-position of the thienylazo moiety a carboxy group, a salt thereof or a hydrolyzable precursor thereof; and(b) a ballasted carrier moiety which is capable of releasing the diffusible 6-(2-thienylazo)-3-pyridinol dye moiety or precursor thereof under alkaline conditions.
摘要:
Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a releasable 6-(2-thienylazo)-3-pyridinol cyan dye moiety or precursor thereof, the compound containing:(a) in the 3-position of the thienylazo moiety a carboxy group, a salt thereof or a hydrolyzable precursor thereof; and(b) a ballasted carrier moiety which is capable of releasing the diffusible 6-(2-thienylazo)-3-pyridinol dye moiety or precursor thereof under alkaline conditions.
摘要:
Process for the preparation of thiophenes having the structure ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be various substituents. The compounds can be converted to the corresponding 2-amino compounds from which azo dyes can be prepared.
摘要:
Photographic elements, diffusion transfer assemblages and processes are described which employ a novel nondiffusible compound having a releasable 6-(2-thienylazo)-3-pyridinol cyan dye moiety or precursor thereof, the compound containing:(a) in the 3-position of the thienylazo moiety a carboxy group, a salt thereof or a hydrolyzable precursor thereof; and(b) a ballasted carrier moiety which is capable of releasing the diffusible 6-(2-thienylazo)-3-pyridinol dye moiety or precursor thereof under alkaline conditions.