2-tert-butyl 4-methyl 3,4-dihydroisoquinoline-2,4(1H)-dicarboxylate(WX142477) synthesis

Yield:-

Reaction Conditions:

with dmap;N-ethyl-N,N-diisopropylamine in dichloromethane at 0 - 20; for 18 h;

Steps:

35.A A 3,4-Dihydro-1H-isoquinoline-2,4-dicarboxylic acid 2-tert-butyl ester 4-methyl ester

To a solution of methyl 1,2,3,4-tetrahydro-isoquinoline-4-carboxylic acid (98 mg; CAS 681448-82-8; Synthetic Communications 34, 137, 2004) in 2 ml dichloromethane under ice cooling, were added successively Boc₂O (223 mg), DIPEA (0.26 ml) and DMAP (6 mg). The reaction mixture was stirred 18 hrs at rt, diluted with AcOEt and washed with 1M HCl, 1M NaOH and brine. The organic layers were dried over magnesium sulfate, evaporated and chromatographed (silica gel, AcOEt/heptane 1/1) to yield the title compound as a yellow oil (135 mg). MS: 292.1 (M+H)⁺.

References:

US2007/112012,2007,A1 Location in patent:Page/Page column 22