Analyzing the synthesis route of 1837-55-4

As the paragraph descriping shows that 1837-55-4 is playing an increasingly important role.

1837-55-4, 3,5-Dichloropyridazine is a pyridazine compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated

Example 95: 5-[(3R)-3-(Methylamino)pyrrolidin-1-yl]-N-(2- methylpropyl)pyridazin-3-arnine. [1 -(delta-Chloro-pyridazin-^yO-pyrrolidin-S-yO-methyl-carbamic acid tert-butyl ester. A solution of 3,5-dichloropyridazine (149 mg, 1.0 mmol) in THF (3 ml_) at 23 0C was treated with (RJ-methyl-pyrrolidin-S-yl-carbamic acid tert-butyl ester (440 mg, 2.2 mmol) and the reaction stirred at 23 0C for 18 h. The reaction diluted with EtOAc (30 ml) and solution washed with water (2 x 5 ml) and combined organic solution dried and concentrated and crude material purified on 16 g SiO2 (O to 30% EtOAc : Hex) to yield 283 mg (91 % yield) of the desired regioisomer and 17 mg (5% yield) of the undesired regioisomer. MS (ESI): mass calcd. for Ci4H2iCIN4O2, 312.5 m/z found, 313.5 [M+H]+. [1 -(delta-lsobutylamino-pyhdazin^-yO-pyrrolidin-S-yO-methyl-carbamic acid tert- butyl ester. A solution of [1-(6-chloro-pyhdazin-4-yl)-pyrrolidin-3-yl]-methyl- carbamic acid tert-butyl ester (32 mg, 0.1 mmol) in isobutylamine (1.0 ml) in a sealed tube was heated to 120 0C for 72 h. The resulting solution was purified directly on 12 g SiO2 (0 to 5% NH3/Me0H:CH2CI2) to yield 20 mg (55% yield). lsobutyl-[5-(3-methylamino-pyrrolidin-1 -yl)-pyhdazin-3-yl]-amine dihydrochlohde. To a stirring solution of [1-(6-isobutylamino-pyhdazin-4-yl)- pyrrolidin-3-yl]-methyl-carbamic acid tert-butyl ester (19 mg, 0.06 mmol) in 96% formic acid (0.5 ml_) was added 0.05 ml of aqueous 6N HCI. The mixture was stirred for 2 hr, diluted with MeOH and concentrated under reduced pressure (repeat 3X) to give the desired product as a white solid (101 mg, >99%). MS (ESI): mass calcd. for Ci3H23N5, 249.4 m/z found, 250.2 [M+H]. 1H NMR (400 MHz, CD3OD): 8.12 (d, J = 2.5, 1 H), 6.08 (s, 1 H), 4.1 1 – 4.01 (m, 1 H), 4.04 – 3.47 (m, 4H), 3.35 (s, 1 H), 3.15 (d, J = 7.0, 2H), 2.82 (s, 3H), 2.65 – 2.53 (m, 1 H), 2.43 – 2.31 (m, J = 5.6, 1 H), 1.96 (dt, J = 13.4, 6.7, 1 H), 1.03 (d, J = 6.7, 6H)., 1837-55-4

As the paragraph descriping shows that 1837-55-4 is playing an increasingly important role.

Reference£º
Patent; JANSSEN PHARMACEUTICA NV; WO2009/152325; (2009); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem