D,L-, L- and D-phenyl alanine derivatives of formula (I) defined in claim 1 in which R.sub.1 is an amidino-, guanidino-, oxamidino-, aminomethyl- or amino group have been discovered which effectively prevent blood coagulation or thrombosis. The antithrombotically active compounds have low toxicity and may be administered by mouth, subcutaneously or intravenously.
在权利要求1中定义的公式(I)中,R.sub.1为酰胺基、
胍基、氧酰胺基、
氨甲基或
氨基的D,L-、L-和
D-苯丙氨酸衍
生物已被发现,可以有效预防血液凝结或血栓形成。这些抗血栓活性化合物具有低毒性,可通过口服、皮下注射或静脉注射给予。