反应详情

A solution of 3.69 g of (trans-4-pentylcyclohexyl)methanol and 5.51 g of triphenylphosphine in 70 ml of methylene chloride at -30° C. was placed under argon gasification and treated portionwise within 15 minutes with 7.30 g of solid tetrabromomethane so that the internal temperature did not exceed -20° C. After completion of the addition, the cooling bath was removed and the mixture was stirred for a further 18 hours with gradual warming to room temperature. The mixture was then concentrated on a rotary evaporator and the semi-crystalline residue obtained was triturated with 200 ml of warm hexane, filtered and the concentrated filtrate was chromatographed with hexane on a column of silica gel. There were obtained 4.79 g (97%) of trans-1-(bromomethyl)-4-pentylcyclohexane as a colourless liquid which was purified further by distillation; b.p. 82° C./0.08 mmHg.

1. customat -30° C.
2. customdid not exceed -20° C
3. additionAfter completion of the addition
4. customthe cooling bath was removed
5. concentrationThe mixture was then concentrated on a rotary evaporator
6. customthe semi-crystalline residue obtained
7. customwas triturated with 200 ml of warm hexane
8. filtrationfiltered
9. customthe concentrated filtrate was chromatographed with hexane on a column of silica gel