SAN FRANCISCO – Apple Inc is in negotiations to purchase chips from two Chinese semiconductor makers on a Pentagon blacklist to help reduce the impact of a global memory shortage that’s forced the company to raise prices across its product line.The iPhone maker is seeking to buy memory components from ChangXin Memory Technologies Inc and Yangtze Memory Technologies Co for use in devices sold in China, according to people familiar with the matter.Talks between Apple and the companies are ongoing, and nothing is final yet, said the people, who requested anonymity to describe private discussions.Apple’s effort has included appeals by…