Réaction #1552130

Équation de réaction

NaOH

NaOH

2-chloro-N-(4-chlorophenethyl)propan-1-amine hydrochloride

aluminum chloride

1,2-dichlorobenzene

→

8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-benzazepine

Conditions de réaction

Traitement

1. 1
   AutreTo a reactor equipped with overhead agitation, jacket temperature control, a nitrogen inlet
2. 2
   AutreAt 60-70° C., a dark colored solution was obtained
3. 3
   AutreAfter reaction completion (<1.0% starting material by HPLC peak area)
4. 4
   Températurethe stirred reactor contents were cooled to 30-35° C
5. 5
   AutreTo a second reactor vented to a caustic scrubber
6. 6
   workup.ADDITIONwas charged
7. 7
   Autrepurified water (1.60 L) and silica gel (0.160 kg)
8. 8
   AutreThe Friedel-Crafts reaction mixture
9. 9
   Températureto maintain the stirred contents of the second reactor at <60° C
10. 10
    FiltrationThe silica gel was filtered on a medium
11. 11
    Filtrationto coarse filter element at 55-60° C.
12. 12
    Lavagethe filtered solids were subsequently washed with purified water (800 mL)
13. 13
    Autrepreheated to 50-60° C
14. 14
    LavageThe combined mother and wash liquor filtrates
15. 15
    Températurewere cooled to 20-25° C. with vigorous agitation
16. 16
    Autreto separate at 20-25° C. (Process volume
17. 17
    AutreThree phases separated after 1-2 hours
18. 18
    workup.WAITto stand without agitation for another 2-4 h
19. 19
    Extractionremained in the reactor for back-extraction
20. 20
    workup.ADDITIONThe reactor was charged with cyclohexane (1.10 kg)
21. 21
    Autreto separate for 25-40 min
22. 22
    workup.ADDITIONOtherwise, more 30% aqueous NaOH was added
23. 23
    Extractionthis extraction
24. 24
    LavageThe reactor was rinsed with purified water
25. 25
    Autreto remove residual salts
26. 26
    workup.STIRRINGThe reactor contents were stirred vigorously for 0.5 hours
27. 27
    Autreto separate over 15-30 minutes
28. 28
    workup.ADDITIONwas added
29. 29
    Autrepurified water (2.40 kg)
30. 30
    workup.STIRRINGThe reactor contents were stirred vigorously at 60-65° C. for 0.5 h
31. 31
    Autreto separate at 60-65° C. over 1.5-2 h
32. 32
    AutreWith a reactor jacket temperature of 55-60° C., solvent from the upper (organic) layer was removed by vacuum distillation at pressures

Mode opératoire

To a reactor equipped with overhead agitation, jacket temperature control, a nitrogen inlet, and a caustic scrubber vent were charged, in the specified order, 2-chloro-N-(4-chlorophenethyl)propan-1-amine hydrochloride (1.00 kg, 3.72 mol), aluminum chloride (0.745 kg, 5.58 mol), and 1,2-dichlorobenzene (2.88 kg). The stirred reactor contents were heated to 125-130° C., and stirring was continued at that temperature for 14-18 h. At 60-70° C., a dark colored solution was obtained. After reaction completion (<1.0% starting material by HPLC peak area) had been verified, the stirred reactor contents were cooled to 30-35° C. To a second reactor vented to a caustic scrubber was charged purified water (1.60 L) and silica gel (0.160 kg). The Friedel-Crafts reaction mixture was transferred from the first reactor to the second reactor sufficiently slowly to maintain the stirred contents of the second reactor at <60° C. After the transfer is completed, the next step may be executed without any hold period. The silica gel was filtered on a medium to coarse filter element at 55-60° C., and the filtered solids were subsequently washed with purified water (800 mL) preheated to 50-60° C. The combined mother and wash liquor filtrates were cooled to 20-25° C. with vigorous agitation. Then the stirring was stopped, and the phases were allowed to separate at 20-25° C. (Process volume peaked at this point at 5.68 L). Three phases separated after 1-2 hours of standing. The lowest layer was drained to waste disposal. This dark layer consisted mostly of 1,2-dichlorobenzene (1.64 kg, 1.33 L) at pH 3-4. About 1% of the product was lost to this layer. The remaining two phases were allowed to stand without agitation for another 2-4 h. The lower layer was drained and saved (Layer A). This light colored phase (2.64 kg, 2.00 L, pH 2-3) contained ˜90% 8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-benzazepine. The upper layer (2.24 kg of a turbid water phase at pH 0-1) contains ˜1-4% 8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-benzazepine and remained in the reactor for back-extraction. The reactor was charged with cyclohexane (1.10 kg) and then 30% aqueous NaOH (2.44 kg, 18.3 mol). The resulting mixture (5.60 L) was stirred vigorously for 30 min at room temperature. The stirring was stopped, and the phases were allowed to separate for 25-40 min. If the pH of the lower (aqueous) phase was ≧13, it was drained to waste disposal. Otherwise, more 30% aqueous NaOH was added, and this extraction was repeated. At pH 14, the aqueous phase contains <0.1% 8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-benzazepine free base. The remaining upper (organic) phase from the reactor was drained and saved (Layer B). The reactor was rinsed with purified water and followed by a suitable organic solvent to remove residual salts. The lower, light-colored product phase (the middle of the original three phases, Layer A) and the upper phase (organic, Layer B) were returned to the reactor. To the stirred reactor contents was added 30% aqueous NaOH (1.60 kg, 12.0 mol). The reactor contents were stirred vigorously for 0.5 hours. The stirring was discontinued and the phases were allowed to separate over 15-30 minutes. The lower (aqueous) layer was drained to waste disposal. To the upper (organic) phase remaining in the reactor was added purified water (2.40 kg). The reactor contents were stirred vigorously at 60-65° C. for 0.5 h. The stirring was discontinued, and the phases were allowed to separate at 60-65° C. over 1.5-2 h. The lower (aqueous) layer was drained to waste disposal. With a reactor jacket temperature of 55-60° C., solvent from the upper (organic) layer was removed by vacuum distillation at pressures starting at 115-152 ton and falling to 40 ton. The crude product, 8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-benzazepine as the free base, was obtained as a yellow to brown oil distillation residue.

Source