JPS6018656B

1517164 Dipeptides ROCHE PRODUCTS Ltd 11 Aug 1975 [20 Aug 1974 21 May 1975] 36567/74 and 21821/75 Heading C3H [Also in Division C2] The invention comprises compounds of the formula wherein R is halogen, NO2 or CF3; R is H or C1-C6 alkyl; R is an acyl group derived from a naturally occurring alpha-amino acid (all such groups which contain an asymmetric C atom having the L-configuration); R is phenyl, halophenyl or pyridyl; and R is H, CH3, cyclopropylmethyl, di - (C1-C4 alkyl) aminoethyl, CH3OCH2- or HOCH2CH2-, and acid addition salts thereof. They may be obtained by (1) cleaving off the protecting group(s) present in a group R in a compound of the above formula wherein R is substituted for R , wherein R is an acyl group derived from a naturally occurring amino acid in which the amino group(s) present is (are) in protected form and any other functional group which may be present is in protected form where required, by known methods; (2) resolving a racemate of Formula Ia into its optical isomers and isolating the L-isomer, or (3) when R is NO2 and R is an acyl group derived from a naturally occurring amino acid which is not affected by nitrating agents, nitrating a compound of the formula wherein R is an acyl group derived from a naturally occurring amino acid which is not affected by nitrating agents; and, if desired, converting a free base into an acid addition salt or converting an acid addition salt into a free base or into a different acid addition salt. The products have useful sedative, muscle relaxant and anti-convulsant activity. The starting materials used in method (1) above may be obtained by condensing a compound of the formula with an appropriately protected dipeptide or a reactive derivative thereof by various methods, e.g. by the mixed anhydride, azide, activated ester or acid chloride method.