Ammonia → HCID 18975712, compound

Participants

Reaction Steps

A solution of 7-methoxy-6-methyl-1-[1-(3-thienyl)cyclopropyl]-3,4-dihydroisoquinoline (2.0 g, prepared in a similar manner to that described in Example 6) in dichloromethane (87 ml) was added slowly to an ice-cooled stirred mixture of sodium tris[(S)-N-(tert-butoxycarbonyl)prolyloxy]borohydride (11.4 g) in dichloromethane (70 ml). After standing at about 4° C. for 2 days a further portion of the reducing agent (2.0 g) was added and the mixture stirred at ambient temperature for 3 hours, then saturated aqueous oxalic acid solution (150 ml) was added. This mixture was stirred for 1 hour then basified with concentrated aqueous ammonia solution and extracted with dichloromethane (4×100 ml). The combined extracts were washed with water (100 ml) then brine (100 ml) then dried over magnesium sulphate and the solvent removed in vacuo to give a pale orange gum. The gum was dissolved in ether (150 ml) and treated with a solution of oxalic acid in ether (0.43M; 20 ml) and the resulting precipitate filtered then recrystallised from ethanol to give a single enantiomer of 7-methoxy-6-methyl-1-[1-(3-thienyl)cyclopropyl]-1,2,3,4-tetrahydroisoquinoline oxalate (1.2 g) which was used without further characterisation.

Provenance & Evidence