HCID 10044381, compound → HCID 70025041, compound

Participants

Reaction Steps

A solution of (S)-1,2,3,4-tetrahydro-6,7-diethoxy-2-(tert-butyloxycarbonyl)-3-isoquinolinecarboxylic acid (example 4) (18.3 g, 0.05 mol), 20% HCl/IPA solution (18.3 g, 0.1 mol) in ethyl acetate (100 mL) was stirred at 40° C. for 3 hrs. The resulting suspension was cooled to room temperature, filtered, and rinsed with ethyl acetate (2×30 mL). The solids were dried under vacuum to give 12.1 g of (S)-1,2,3,4-tetrahydro-6,7-diethoxy-3-isoquinolinecarboxylic acid. Yield 81%. 1H NMR (DMSO-d6) δ: 1.32 (t, J=6.9 Hz, 6H, CH2CH3), 3.03 (dd, J=16.7, 10.9 Hz, 1H, CHHCHCOOH), 3.21 (dd, J=16.7, 4.9 Hz, 1H, CHHCHCOOH), 3.9-4.06 (m, 2H, CH2CH3), 4.2 (br s, 2H, CH2N), 4.33 (dd, J=10.9, 4.9 Hz, 1H, CHCOOH), 6.84, 6.85 (s, 2H, PhH), 9.96 (br s, 2H, NHHCl).

Provenance & Evidence