Oblon, Spivak, McClelland, Maier & Neustadt
Azulenesquaric acid dyes, azulene intermediates therefor, and optical recording medium
 Azulenesquaric acid dyes of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 each have specified meanings are prepared from azulene derivatives of the formula ##STR2## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 each have specified meanings as intermediates, and used in an optical recording medium. 
BASF Aktiengesellschaft
C
C09B
inventional
Sibylle Harald Klaus D. Peter Wolfgang Helmut
Brosius Kuppelmaier Schomann Neumann Schrott Barzynski