Method of producing 1-N-[L-(-)-.alpha.-hydroxy-.gamma.-aminobutyryl]XK-62-2

A process for producing a compound of the formula:

• ##STR19## which comprises reacting a compound of the formula:
• ##STR20## with an acylating agent selected from the group consisting of:
• ##STR21## wherein R.sub.1 and R.sub.2 may be the same or different and are H, OH, NO.sub.2, Cl, Br, I, alkyl groups having 1 to 5 carbon atoms or alkoxy groups having 1 to 5 carbon atoms, respectively, R.sub.3 is H, F, Cl, Br, I or an alkyl group having 1 to 5 carbon atoms and X is Cl, Br or I;
• or an amino protecting reagent selected from the group consisting of:
• ##STR22## wherein X has the same significance as defined above to introduce an eliminable protecting group to the amino group bound to the carbon atoms at the 2' and 6' positions to prepare a first intermediate compound represented by the formula ##STR23## wherein R.sub.1, R.sub.2 and R.sub.3 have the same significance as defined above, Y.sub.2 has the same significance as Y.sub.1 and Y.sub.3 is hydrogen, or Y.sub.2 and Y.sub.3 form a phthaloyl group;
• acylating said first intermediate compound with an acylating agent derived from .alpha.-hydroxy-.gamma.-aminobutyric acid represented by the formula:
• ##STR24## wherein Y.sub.4 is H and Y.sub.5 is ##STR25## wherein R.sub.1, R.sub.2 and R.sub.3 have the same significance as defined above or Y.sub.4 and Y.sub.5 form a phthaloyl group;
• and Z is ##STR26## to prepare a second intermediate compound represented by the formula:
• ##STR27## wherein Y.sub.1, Y.sub.2, Y.sub.3, Y.sub.4 and Y.sub.5 have the same significance as defined above;
• and
• thereafter eliminating said protecting groups wherein said reaction to prepare said first intermediate compound is carried out at a temperature from -50.degree. to 50.degree. C for from 1/4 to 24 hours and wherein from 1.0 to 4.5 moles of said acylating agent having the formula ##STR28## or said amino protecting reagent is employed per mole of ##STR29## and wherein said first intermediate compound is acylated to prepare said second intermediate compound at a temperature from -50.degree. to 50.degree. C for from 1/4 to 24 hours employing 0.5 to 1.5 moles of said acylating agent having the formula ##STR30## per mole of said first intermediate compound.