Isochroman 3-amino

A mixture consisting of 4 grams of 1,2,3,4-tetrahydro-4,4-dimethyl-7-methoxy-isochromane-dione-(1,3) (MP 95° to 97°C), 2.53 grams of 4-aminosulfonyl-phenyl-(2)-ethylamine and 150 ml of xylene was heated for 2 hours at its boiling point in an apparatus provided with a water separator. Thereafter, the reaction mixture was allowed to cool and was then vacuum-filtered, and the filter cake was recrystallized from n-propanoi in the presence of activated charcoal. 2.9 grams (58% of theory) of 1,2,3,4-tetrahydro-4,4-dimethyl-2-(p-amino-sulfonylphenyl-(2)-ethyl]-7-methoxy-isoquinolinedione-(1,3), MP 203° to 205°C, of the formula below were obtained. 

Naphthyridine 390 is synthesized from 4-amino-3-pyridinecarbal-dehyde 388 and isochroman-4-one 389 in 50% yields (Scheme 86) (03CJOC466). 

Ort/io-lithiated aryloxiranes proved to be quite effective also in promoting nucleophilic conjugate additions toward p-amino-a,p-enones 78 for the one-pot multistep synthesis of functionalized isochromanes 81 (Scheme 21) (2013JOC11059). 

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