Synthesis and reactions of 4-amino-3-carbethoxy-1,2-dihydrospiro(naphthalene-2,1′-cyclopentane)

Addition of benzylmagnesium chloride to cyclopentylidenecyanoacetic ester gives 1-benzyl-1-(cyanocarbethoxymethyl)cyclopentane and this can be cyclized to 4-amino-3-carbethoxy-1,2-dihydrospiro-(naphthalene-2,1′-cyclopentane). Acylation of the obtained aminoester with carboxylic acid chlorides produces the corresponding amides (which can react with an excess of benzoyl chloride). It can also react with orthoformic ester. In both cases the product can then react with hydrazine hydrate. Treatment of the same aminoester with caprolactam gives a tetrahydrospiro(benzo[h]quinazoline-5,1′-cyclopentane) derivative.