Hydrochloric Acid → HCID 67916769, compound

Participants

Reaction Steps

Diisobutyl aluminium hydride (142 ml of a 1M solution in hexane) was added dropwise to a stirred solution of 2,6-di-tert-butyl-4-methylphenol (62.24 g) in dry toluene (590 ml) at 4° under nitrogen. After stirring for 45 min the mixture was cooled to -60° and a solution of the free base of the product of Example 8, (5.2 g) in dry toluene (95 ml) was added over 5 min. The reaction mixture was stirred at -60° for 2 h and allowed to warm to room temperature and stirred at room temperature for a further 1 h. Dilute hydrochloric acid (1M, 500 ml) was added and the resulting mixture was stirred vigorously for 1 h. The layers were separated and the aqueous layer was washed with ether (500 ml), basified with aqueous sodium hydroxide (2M, 500 ml) and extracted with dichloromethane (3×500 ml). The dichloromethane extracts were combined, dried and evaporated to give the free base of the title compound as a foam (4 g) which was shown by g.l.c. to have a cis:trans ratio of 98.6:1.4. A portion of the foam (1 g) was dissolved in a mixture of ether (40 ml)/ethyl acetate (10 ml) and an ethereal solution of hydrogen chloride was added to give a solid (1.07 g). This solid was crystallised from a mixture of ethanol (20 ml)-ethyl acetate (20 ml) to give the title compound (669 mg) as a solid, m.p. 202°-203°.

Provenance & Evidence