Nippon Electric Co., Ltd.

Sanko Chemical Company Ltd.

Yasuo Kato

Yoshio Matsuo

Hideo Nagasawa

Shoji Miki

Yumiko Ishikawa

Shiro Kimura

Yasuyoshi Nakamura

A compact transmitter-receiver circuit particularly adapted for short-distance mobile communication includes a pair of parallel nonlinear circuits, first and second hybrid circuits connected to the pair of nonlinear circuits on their high- and low-frequency sides, respectively, and a radio-frequency generator and a driver circuit connected to the respective hybrid circuits. One of the four terminals of the first hybrid circuit serves as a common input-output terminal of the transmitter-receiver circuit without necessitating any particular means conventionally required for separation between transmission and reception signals.

Transmitter-receiver circuit

A process for the preparation of 4-amino-3-methyl-N-substituted or unsubstituted alkylanilines comprising acylating and/or sulfonylating 4-amino-3-methyl-nitro-benzene having the formula (I) ##STR1## with an acylation or sulfonylation agent to obtain a compound having the general formula (II) ##STR2## wherein R.sub.1 represents a hydrogen atom or an acyl group, R.sub.2 represents an acyl group or a sulfonyl group, or R.sub.1 and R.sub.2 can combine as a difunctional acyl group; reducing the nitro group of the compound having the general formula (II) with hydrogen in the presence of a metal hydrogenation catalyst to obtain a compound having the general formula (III) ##STR3## wherein R.sub.1 and R.sub.2 are as above defined; alkylating the amino group of the compound having the general formula (III) with an alkylation agent selected from the group consisting of an alkyl halide, a substituted alkyl halide and an alkylene oxide to obtain a compound having the general formula (IV) ##STR4## wherein R.sub.1 and R.sub.2 are as above defined, R.sub.3 represents an alkyl group or a substituted alkyl group and R.sub.4 represents a hydrogen atom, an alkyl group or a substituted alkyl group; and hydrolyzing the compound having the general formula (IV) to obtain a compound having the general formula (V) ##STR5## wherein R.sub.3 and R.sub.4 are as above defined.

Process for preparing 4-amino-3-methyl-N-substituted or unsubstituted

Growing community of inventors

Tokyo, Japan

Yasuo Kato