less water can be used the term 34 polar organic solvent 34 includes solvents such as organic amides lower alkanols dimethyl sulfoxide tetrahydrofuran acetonitrile acetone dioxane and the like or a mixture of such solvents organic amide solvents such as formamide acetamide and dimethylformamide are especially useful solvents in the process in this invention for example compound 2 is dissolved in formamide with warming about two volumes of water are added to the formamide solution hydrochloric acid is added until the solution has a ph of about 2 and compound 1 is allowed to crystallize lower alkanols such as ethanol are also especially useful solvents in the process of this invention ethanol is particularly advantageous because it is relatively non toxic when ethanol is used typically compound 2 is slurried in warm ethanol concentrated hydrochloric acid is added to the slurry dissolving compound 2 in the solution which forms and compound 1 is allowed to crystallize concentrated hydrochloric acid is preferably used in the process of this invention since more dilute solutions of the acid result in larger volumes of crystallization solution it is especially desirable to avoid larger volumes whenever possible in large scale crystallizations hydrochloric acid solutions having a concentration of about 12n are especially useful the process of this invention is carried out conveniently by warming the solution containing compound 1 to temperatures of about 30 u00b0 to about 45 u00b0 c initially and subsequently cooling it to room temperature or below after crystallization the hydrochloride salt.