1-Propanol → HCID 58392570, compound

Participants

Reaction Conditions

Reaction Steps

To an appropriately-sized reactor was charged 1-bromo-2-fluoro-4-iodobenzene (600.55 g, 1.996 mol, 1.0 eq.), 3-fluorophenylboronic acid (282.60 g, 2.020 mol, 1.01 eq.), sodium bicarbonate (503.91 g, 5.998 mol, 3.0 eq.), trans-dichlorobis(triphenylphosphine)palladium(II) (4.1947 g, 5.98 mmol, 0.003 eq.), n-propanol (4.8 L, 8 vol. relative to trihalide amount), and water (2 vol. relative to trihalide amount). The mixture was stirred at a speed adequate to produce an evenly-dispersed suspension. The reaction solution was evacuated and degassed, backfilling with nitrogen or argon. The reaction mixture was heated to a target of 83±5° C. Once the target temperature was reached, the temperature was maintained for 14-20 hours. Reaction completion was determined using HPLC (trihalide RT: 5.9 min; product RT: 7.6 min), with <1% remaining starting material being the target for completion. Upon complete reaction, the mixture was cooled to 25±5° C. The mixture was then quenched with 1 M NaOH (aq) (6 L, 10 vol) and stirred to mix phases thoroughly. n-Heptane was added (6 L, 10 vol) and stirred to mix phases thoroughly. Stirring was stopped and the phases were allowed to separate. The aqueous phase was drained and discarded. The organic phase (top) was washed with 1 M NaOH (aq) (6 L, 10 vol) and 2% (w/w) NaCl (aq) (6 L, 0 vol) successively, discarding the aqueous phase. The organic phase was concentrated in the reaction vessel using reduced pressure to approximately 2 volumes; the vessel did not exceed 45° C. for the pot temperature; the typical vacuum for the distillation was 70-110 torr. n-Heptane (3 L, 5 vol) was added to the mixture and stirred to cool to 25±5° C. The solution was filtered through a column packed with silica gel (8.5 cm tall×5.5 cm diameter pad of silica gel made using 72 g; loading: 120 g of silica gel per kg of trihalide added). The reaction flask was rinsed with n-heptane (0.6 L, 1 vol) and the solution was filtered through the silica gel column. The rinse was repeated once. The solution of crude E-3a in n-heptane was transferred to the distillation flask. The solution was distilled to a total of approximately 2 (˜1.2 L) volumes relative to the trihalide amount. The pot temperature did not exceed 45° C. The typical vacuum for the distillation was 70-110 torr. The concentration of the solution was determined using weight/weight assay. For preparation of a reference marker (high purity E-3a), the crude solution after workup and filtration was purified using vacuum distillation and the product was boiled at approx. 180° C., with 21 mmHg. This reaction may be performed on a kilogram scale. For example, this reaction has been successfully performed to obtain approximately 20 kg of product.

Provenance & Evidence