The isolation and characterization of some 1‐alkyl‐2‐acyl‐1,2‐dihydroisoquinaldonitriles

Heterocyclic monomers via reissert chemistry

“…We previously found that isoquinoline Reissert compound 1 , R = C 6 H 5 had a strong tendency to rearrange rather than alkylate, whereas the Reissert compound 29 from ortho toluyl chloride was alkylated in good yield 16. In fact, even in the absence of an electrophile, the anion from the o ‐toluyl Reissert compound 29 did not rearrange.…”

“…The most probable reason for the low molecular weights of 28a and 28b is rearrangement of the Reissert anion. Monomeric benzoyl Reissert compounds are known to rearrange (Scheme ) and sometimes this rearrangement reaction is preferred over alkylation 16. Thus, the rearrangement could be expected in the polymerization reactions of the bis(Reissert compound)s with dihaloalkanes, especially as the substrates are consumed and the rate of alkylation slows, and this would alter the stoichiometry and lead to low molecular weight.…”

“…To a stirred solution of o ‐toluyl Reissert compound 29 16 (1.000 g, 3.64 mmol) and n ‐bromobutane (0.4988 g, 3.64 mmol) in 20 mL DMF at 0 °C, NaH (0.1602 g, 60% dispersion, 4.00 mmol) was added. The solution immediately turned dark red; stirring was continued for 4 h. The solution was poured into 200 mL of water and the resulting white solid was filtered and dried, 1.22 g (100%).…”

“…The anions react with alkyl halides, forming 1‐alkyl derivatives 4 , whose basic hydrolysis affords 1‐alkylisoquinolines ( 5 ) through rearomatization (Scheme ) 8, 12(d), 15, 16. An intramolecular rearrangement in the absence of an electrophile converts the Reissert anion into ketone 6 8, 12(d), 15.…”

“…An intramolecular rearrangement in the absence of an electrophile converts the Reissert anion into ketone 6 8, 12(d), 15. The tendency to undergo rearrangement versus alkylation depends on the nature of the acyl group (Scheme ) 16…”