| 摘要 |
This invention relates to a process for preparing the compound of formula (I I) which comprises treating the compound of formula (IIIA) wherein YH is (R)-CS A or L-DTTA with hydrogen in the presence of a precious metal catalyst, preferably Pd(OH)2. The compounds of formula (II) are useful in the preparation of compounds of formula (I) wherein Ar is an optionally substituted 5-8 membered heteroaryl or optionally substituted benzene fused optionally substituted heteroaryl ring wherein said heteroaryl ring comprise s 1 to 4 heteroatoms selected from nitrogen, oxygen and sulfur; which are usef ul for inhibiting the production of leukotrienes and/or blocking leukotriene receptors and in the prevention or treatment of asthma, arthritis, psoriasis , ulcers, myocardial infarction and related disease states in mammals. The invention also relates to compounds of formulae (IVA); (IVB); (IIIC); (IIIB) and (IIID).
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