ChemicalBook CAS DataBase List Bromonordiazepam

Bromonordiazepam synthesis

10synthesis methods

Product Name:Bromonordiazepam
CAS Number:2894-61-3
Molecular formula:C15H11BrN2O
Molecular Weight:315.16

56-40-6 Synthesis

56-40-6
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2H-1,4-Benzodiazepine-2-thione, 7-bromo-1,3-dihydro-5-phenyl-

34099-70-2
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Glycine, N-(7-bromo-5-phenyl-3H-1,4-benzodiazepin-2-yl)-

612527-22-7
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2894-61-3
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Yield:612527-22-7 67%

Reaction Conditions:

with water;sodium carbonate in ethanol; for 5 h;Heating / reflux;

Steps:

suspension of 7-bromo-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-thione 84 (1.6 g, 4.83 mmol), glycine (1.81 g, 24.2 mmol) and Na₂CO₃(1.84 g, 17.4 mmol) in EtOH (38 mL)-H₂O (16 mL) was stirred at reflux for 5 h, poured into water (100 mL), and then filtered to remove a small amount of 7-bromo-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one which remained. See Archer G A, Sternbach L H (1964) J Org Chem 29:231. The filtrate was extracted with CHCl₃. The CHCl₃extract was discarded; the aqueous layer was adjusted to pH 4 with 2N HCl and then extracted with CHCl₃(3×25 mL). Evaporation of the CHCl₃solution gave pure acid 85 (1.2 g, 67%) as a yellow solid. Acid 85 (350 mg, 0.941 mmol) was suspended in dry CH₂Cl₂(10 mL) and DCC (223 mg, 1.08 mmol) was added. The suspension which resulted was stirred at 40° C. for 2 h and then cooled to 0° C. It was filtered, and the solvent was removed under vacuum to give 8-bromo-2,4-dihydro-6-phenyl-1H-imidazo[1,2-a][1,4]benzodiazepin-1-one 86 as a brown oil. The cyclized product 86 (ca. 250 mg) was dissolved in dry benzene (6 mL), dimethylformamide diethylacetal (130 mg, 0.883 mmol) and triethylamine (89 mg, 0.883 mmol) were added. The solution which resulted was stirred at room temperature for 1 h and the solvent was removed under vacuum, The residue was then crystallized from EtOAc-MeOH to give 87 (200 mg, 70%). A solution of 87 (180 mg, 0.440 mmol) in dry toluene (5 mL) was treated with 1-methyl piperazine (1 mL) and heated to reflux for 5 h. The solvent was removed in vacuum to give a gum which crystallized from CH₂Cl₂-Et₂O to furnish 88 (PS-I-35, 146 mg, 72%). mp>250° C.; IR (KBr) 3324, 2932, 2787, 1692, 1624, 1475, 1402, 1297, 1137, 933 cm^-1; ¹H NMR (CDCl₃) δ 7.95 (d, 1H, J=8.8 Hz), 7.72 (dd, 1H, J=2.3 Hz, J=8.8 Hz), 7.58-7.55 (m, 2H), 7.49-7.37 (m, 4H), 7.17 (s, 1H), 5.01 (d, 1H, J=12 Hz), 4.50-4.60 (m, 1H), 4.20-4.30 (m, 1H), 4.16 (d, 1H, J=12 Hz), 3.50-3.58 (m, 2H), 2.40-2.60 (m, 4H), 2.34 (s, 3H); MS (m/z) 465 (100). Anal. Calcd. for C₂₃H₂₂N₅OBr.H₂O: C, 58.79; H, 4.95; N, 14.89. Found: C, 58.73; H, 4.86; N,