Loratadine Impurity 17 synthesis

Yield: 100%

Reaction Conditions:

Stage #1:8-chloro-5,6-dihydro-11H-Benzo[5,6]cyclohepta[1,2-b]pyridin-11-one with sodium tetrahydroborate in methanol at 0 - 20; for 1 h;
Stage #2: with hydrogenchloride in methanol;water

Steps:

3.E
The title compound of Step D (700 mg) above was dissolved in MeOH (10 ml) and cooled to 0⁰C. NaBH₄ (95 mg) was added in one portion. The mixture was allowed to warm to RT and stirred for 1 h. The reaction was acidified with 1 N HCl and subsequently, brought to pH 12 with 1 N NaOH. The mixture was poured in water (100 ml) and extracted with CHCl₃ (100 ml). The organic phase was dried over MgSO₄ and concentrated affording the title compound (705 mg; 100 %).¹HNMR δ (MeOD-dO 3.0-3,4 (m, 4H), 6.1(s, IH), 7.1.7.3 (m, 3H), 7.5-7.6 (m, 2H), 8.3:8.4 (m, IH)

References:

ALANTOS PHARMACEUTICALS, INC. WO2006/116157, 2006, A2 Location in patent:Page/Page column 56; 58