A process for producing a compound represented by the following formula (1d) or a salt or hydrate thereof: ** Formula ** in which R1a represents a di (C1-C6 alkyl) amino group； and R4 represents a C1-C6 alkyl group or a benzyl group (in which the benzyl group may have, in the benzyl ring, one or two groups as substituents selected from the group consisting of a C1-C6 alkyl group, a C1-C6 alkoxy group, a nitro group and a halogen atom), in which the process comprises: treating a compound represented by the following formula (4): ** Formula ** in which R1a is as defined above , with the following [solution A]: [Solution A] prepared by treating, in a solvent, a compound represented by the following formula (I): R4-OH (I) in which R4 is as defined above, with chlorosulfonyl isocyanate and a tertiary amine； or with the following [reagent B]: [Reagent B] which is a compound represented by the following formula (II): ** Formula ** in which R4 represents a C1-C6 alkyl group or a benzyl group (in which the benzyl group may have, in the benzyl ring, one or two groups as substituents selected from the group consisting of a C1-C6 alkyl group, a C1-C6 alkoxy group, a nitro group and a halogen)； and R21 and R22 represent the following a), b) or c): a) R21 and R22 are identical or different and each represents a C1-C6 alkyl group； (b) R22 represents a C1-C6 alkyl group, and the two R21s, together with the nitrogen atom to which the R21s binds, form a piperidine ring, a pyrrolidine ring or a 1,4-morpholine ring； or (c) the two R21s and R22, together with the nitrogen atom to which R22 and R21s bind, form an octane 1,4-diazabicyclo [2.2.2] ring or a quinuclidine ring, to obtain a compound represented by the following formula (5): ** Formula ** in which R1a and R4 are as defined above, treating, in the presence of a base, the compound represented by the formula (5) with a compound represented by the formula (III) as follows: R6SO2X (III) in which R6 represents a C1-C6 alkyl group, a
